4,852 research outputs found
Greek Life By Heck!
No full textA coloring book of cartoons from the 1929 Sibyl, drawn by J. Parker Heck (class of 1930).These coloring pages are cartoon illustrations that were published in the “Social Groups” section of the 1929 Sibyl, with additional facts about the fraternities and sororities taken from the Otterbein University Archives.18 pages, 8 ½” x 11”.https://digitalcommons.otterbein.edu/coloring/1003/thumbnail.jp
Estudos cenéticos da reação de heck intramolecular catalisada por nanopartículas bimetálicas estabilizadas por polietilenoimina linear funcionalizada
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-graduação em Química, Florianópolis, 2013Reações de acoplamento C-C tem grande destaque na síntese de novos compostos orgânicos, em especial a reação de Heck. Porém, o desenvolvimento de novos sistemas catalíticos, com metodologias livres de ligantes fosfina, ausência de atmosfera inerte e realizadas em meio aquoso, tem sido um grande desafio nos últimos anos. Ainda, dos poucos trabalhos relatados nesta área, raros são os que se dedicam ao estudo sistemático dos mecanismos de reação. Neste sentido, este trabalho pretende contribuir no desenvolvimento de novos catalisadores para reações de acoplamento C-C, nas condições anteriormente citadas, baseando-se no preparo e caracterização de nanopartículas bimetálicas de prata e paládio, estabilizadas por polietilenoimina linear, e sua aplicação em uma reação do tipo Heck intramolecular. Análise Cinética do Progresso da Reação foi utilizada para a determinação da ordem da reação em relação aos reagentes e obtenção de evidências mecanísticas. Também foi verificada a influência da base utilizada (trietilamina) na reação e sobre a morfologia do catalisador. Por fim, experimentos de inibição do catalisador e análise por microscopia eletrônica de transmissão das nanopartículas, após a reação, sugerem a participação da superfície das nanopartículas na catálise de Heck sob as condições estudadas. Abstract: Carbon-carbon coupling is a prominent reaction in the synthesis of new organic compounds, specially the Heck reaction. However, the development of new catalytic systems, with methods free of phosphine ligands, without inert atmosphere and held in an aqueous medium, has been of great challenge in the last years. Moreover, from the few studies reported in this area, very little are dedicated to the systematic study of reaction mechanisms. Thus, this work aims to contribute in the development of new catalysts for C-C coupling reactions, under the conditions previously mentioned, based on the preparation and characterization of bimetallic nanoparticles of silver and palladium, stabilized by linear polyethyleneimine, and its application in an intramolecular Heck type reaction. Reaction Progress Kinetic Analysis was used to determine the reaction order with respect to reactants and obtention of mechanistic evidences. It was also verified the influence of the base (triethylamine) on the reaction and on the catalyst morphology. Finally, catalyst inhibi-tion experiments and analysis by transmission electron microscopy of the nanoparticles, after the reaction, suggest the involvement of the nanoparticles surface on catalysis under the studied conditions
Estudos cinéticos de uma reação de Heck intramolecular em meio aquoso catalisadas por nanopartículas de paládio suportadas em polietilenoimina ramificada
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2013Reações de acoplamento Carbono-Carbono do tipo Heck, em meio aquoso, tem se destacado como uma nova forma de realizar síntese orgânica, com uma metodologia mais barata, segura e confiável para a construção de diferentes moléculas. Até o momento poucos trabalhos foram dedicados ao estudo mecanístico destas reações. Neste sentido, este trabalho envolve a preparação, caracterização e o emprego de colóides de paládio, estabilizados pelo polímero comercial polietilenoimina, como catalisador em uma Reação de Heck Intramolecular, na presença de base, usando água como solvente e sem controle da atmosfera. O estudo dos diversos aspectos que influenciaram a velocidade da reação, assim como também a conversão ao produto, foi realizado por uma nova metodologia cinética. Análise Cinética do Progresso da Reação foi aplicada e pelos resultados obtidos foi observado que a reação é de primeira-ordem em relação ao catalisador e ordens em relação aos outros reagentes. Além disso, identificou-se uma forte relação, tanto na velocidade da reação quanto na conversão ao produto, com as concentrações iniciais da base. A análise destes resultados, aliados à estudos morfológicos das nanopartículas de paládio por microscopia eletrônica de transmissão, indicam a participação da superfície da nanopartícula e a alteração de seu tamanho durante o progresso da reação. Ainda, nas condições reacionais estudadas foi possível obter até 90% de conversão a produto após 24 horas, sem uso de atmosfera inerte e em condições brandas de temperatura.Abstract : Carbon-Carbon Heck coupling reactions, in aqueous media, have become a new way to make organic synthesis, as a cheaper, safer and more reliable methodology to build different molecules. So far only a few works have been dedicated to the mechanistic studies of these reactions. Through this way, the present work involves the preparation, characterization and the use of palladium colloids, stabilized by the commercial polymer polyethyleneimine, in an Intramolecular Heck Reaction, in the presence of a base, using water as the reaction solvent and without control of the atmosphere. The study of the different aspects that influenced the reaction rate, as well as the product conversion, was performed by a new kinetic methodology. Reaction Progress Kinetic Analysis was applied and from the results it was observed that the reaction is first-order in respect to the catalyst and have complex orders in respect to other reactants. Besides, it has been identified a strong relationship of the reaction rate, and product conversion, with the initial concentrations of the base. Analysis of these results, allied to the palladium nanoparticles morphological studies by transmission electron microscopy, indicated a participation of the nanoparticle#s surface and its size shifting during the reaction progress. Moreover, in the reaction conditions studied it was possible to obtain up to 90% of conversion to product in 24 hours without inert atmosphere and under mild conditions of temperature
Nanocatalisadores metálicos de paládio e prata estabilizados com novos líquidos iônicos piridínicos para aplicação em reações de Heck e redução
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2015.Este trabalho foi dividido em: (i) síntese de novos líquidos iônicos (LIs) piridínicos para utilização na estabilização de nanopartículas de prata (Ag-NPs) para aplicação na reação de redução do p-nitrofenol (NIP) e (ii) a introdução da ciclização do N-(o-iodobenzoil)-3-metilindol (MIAc), como modelo de reação de Heck para avaliação in situ, por espectroscopia UV-visível (UV-vis), da atividade de catalisadores a base de paládio molecular ou coloidal. Nove LIs foram sintetizados variando-se a cadeia alquílica ligada ao nitrogênio piridínico (metil, butil e octil) e contra-íons (haletos, tetrafluoroborato (BF4) e bis(trifluorometilsulfonil)imidato (NTf2)) e utilizados na estabilização de Ag-NPs. Para comparar os nove sistemas Ag-NPs/LI, verificou-se sua atividade catalítica na reação de redução do NIP, cujo progresso é facilmente monitorado por UV-vis. Todos os nanocatalisadores apresentaram atividade na redução do NIP sendo que, em geral, as maiores constantes de velocidade foram obtidas quando LIs metilados foram utilizados como estabilizante. Na reação de ciclização do MIAc, três sistemas catalíticos foram testados: nanopartículas de paládio (Pd-NPs/LI-Me(I)) pré-formadas e estabilizadas pelo LI N-metilpiridínico (LI-Me(I)); Pd(OAc)2 e Pd(OAc)2 com adição de LI-Me(I) (Pd(OAc)2/LI-Me(I)). Diversos experimentos foram realizados como variação da quantidade do catalisador, da concentração e natureza da base, do solvente e do LI, além de análises por microscopia eletrônica de transmissão (TEM) em diferentes tempos de reação e envenenamento com Hg. Após essa série de experimentos, pode-se dizer que a ciclização do MIAc foi introduzida com êxito como modelo de reação de Heck uma vez que seu progresso foi acompanhado in situ por UV-vis facilitando a realização de diversos experimentos para obtenção dos parâmetros cinéticos TON (mol de catalisador/mol de produto) e TOF (TON/tempo), com os quais comparou-se a atividade e aplicabilidade de sistemas catalíticos a base de paládio. Além disso, demonstrou ser uma reação relativamente branda ocorrendo em meio aquoso, na ausência de atmosfera inerte e a 80 ºC. O sistema Pd(OAc)2/LI-Me(I), com 1x10-3 mmol L-1 de LI-Me(I), resultou nos maiores parâmetros TON e TOF e maior conversão ao produto de ciclização.Abstract : The present work is divided in: (i) synthesis of new pyridinium ionic liquids (LIs) to use as stabilizing agents of silver nanoparticles (Ag-NPs), whose application was the reduction reaction of p-nitrophenol (NIP) and (ii) the introdution of (2-iodophenyl)(3-methyl-1H-indol-1-yl)methanone (MIAc) ciclization as a model reaction, for the in situ evaluation by UV-vis Spectroscopy (UV-vis) of Pd catalysts based on molecular or colloidal palladium. Nine LIs were synthesized modifying the alkyl chain bounded to the pyridine nitrogen (methyl, butyl and octyl) and the counteranion (halides, tetrafluoroborate (BF4-) and bis(trifluoromethylsulfonyl)imidate (NTf2-)). To compare the nine Ag-NPs/LI systems, their catalytic activity was evaluated in the NIP reduction reaction, whose progress can be easily monitored by UV-vis. All Ag-NPs/LI catalyst showed a good catalytic activity for the NIP reduction but, in general, the highest rate constants were obtained with methylic LIs. For the MIAc ciclization, three catalytic systems were evaluated: as-formed palladium nanoparticles (Pd-NPs/LI-Me(I)) stabilized by N-methylpyridinic LI, Pd(OAc)2, and Pd(OAc)2 with LI-Me(I) addition (Pd(OAc)2/LI-Me(I)). A series of experiments was carried out including varying the amount of catalyst, the concentration and nature of the base, solvent, and LI, analysis by transmission electronic microscopy (TEM) at different times of the reaction and poisoning tests with Hg. After this series of experiments, it can be said that the cyclization of MIAc was successfully introduced as a model for Heck reaction since its progress was easily monitored in situ by UV-vis, facilitating the implementation of several experiments and obtaining the kinetic parameters TON (mol of product/mol of catalyst) and TOF (TON/time), in which the activity and applicability of the catalytic systems could be compared. Furthermore, the reaction was carried out at relatively mild conditions once it occurs in aqueous medium, in the absence of inert atmosphere, and at 80 ° C. The Pd(OAc)2/LI-Me(I) system with 1x10-3 mmol L-1 of LI-Me(I) resulted in both, highest kinetic parameters TON and TOF and ciclization product conversion
Furthering research and practice in school-university partnerships in the context of preservice teacher education
No full textBeyond boundaries in teacher education: Promoting collaboration and partnership
Together with my colleagues, Associate Professor Debbie Heck from the University of the Sunshine Coast and Dr Helen Grimmett from Monash University, I have an interest in engaging in furthering research and practice in school-university partnerships in the context of preservice teacher education. Since 2014, when I was appointed the Director of the Master of Teaching (Primary) program at The University of Queensland, Debbie, Helen and I have been using innovative strategies such as cogenerative dialogues and metalogues to investigate how effective school-university partnerships may be developed and sustained. Simultanesously, we have explored these and other dialogic pedagogies together with the concept of cogenerativity to probe the notion of teacher professionalism – both for preservice teachers and our own as teacher educators. Debbie, Helen, and I have continued to collaborate over the past five years, having benefited from earlier TERI ventures and translation of our participation in these activities into international publications (peer-reviewed journal articles and chapters) and national conference presentations. A list of relevant outputs follows:
Forgasz, R., Heck, D., Williams, J., Ambrosetti, A., & Willis, L.-D. (2018). Theorising the third space of Professional Experience partnerships. In J. Kriewaldt, A. Ambrosetti, D. Rorrison, & R. Capeness (Eds.), Educating future teachers: Innovative perspectives in professional experience, (pp. 33–47). Springer: Singapore.
Grimmett, H., Heck, D., & Willis, L.-D. (2018). Becoming dialogical practitioners in initial teacher education classrooms. In Australian Association for Research in Education (AARE) Conference, Education Research Matters: Impact and Engagement, 2-6 December 2018, Sydney University, Sydney, New South Wales.
Heck, D., Forgasz, R., White, S, Williams, J., Tobin, K, Ambrosetti, A., & Willis, L.-D. (2016). Theorising the third space of professional experience partnerships. Australian Teacher Education Association (ATEA) Conference, 3-6 July 2016, Ballarat, VIC.
Heck, D., Grimmett, H., & Willis, L.-D. (2017). Using metalogue to develop an understanding of cogenerativity and school-university partnerships in initial teacher education. In Australian Association for Research in Education (AARE) Conference, Education: What’s politics got to do with it?, 26-30 December 2017, Hotel Realm Canberra, Canberra.
Heck, D., Grimmett, H., & Willis, L.-D. (2019 in press). Teacher educators using cogenerative dialogue to reclaim professionalism. In A. Gutierrez, J. Fox, & C. Alexander, Professionalism and teacher education: Voices from policy and practice, (Chapter 7). Springer: Singapore.
Willis, L.-D. (2016). Exploring cogenerativity for developing a coteaching community of practice in a parent-teacher engagement project. International Journal of Educational Research, 80,124–133. doi: http://dx.doi.org/10.1016/j.ijer.2016.08.009
Willis, L.-D., Grimmett, H., & Heck, D. (2018). Exploring cogenerativity in initial teacher education school-university partnerships using the methodology of metalogue. In J. Kriewaldt, A. Ambrosetti, D. Rorrison, & R. Capeness (Eds.), Educating future teachers: Innovative perspectives in professional experience, (pp. 49–69). Springer: Singapore.
Willis, L.-D., Heck, D., & Grimmett, H. (2019 submitted). Can LEGO® Serious Play® help teacher educators better understand the notion of professional identity? Australian Teacher Education Association (ATEA) Conference, 3-5 July 2019, Sunshine Coast, QLD.No Full Tex
Bilder-Atlas zum Conversations-Lexicon, Johann Georg Heck, 1849
No full textBilder-Atlas zum Conversations-Lexikon : Ikonographiche Encyklopadie der Wissenschaften und Kunste / entworfen und nach den vorzuglichsten Quellen bearbeitet von Johann Georg Heck. Images consist of a selection of sixteen illustrations from the 1849 edition of Bilder-Atlas zum Conversations-Lexicon by Johann Georg Heck. Two of the illustrations show mid-19th century surgical procedures and instruments. The remaining illustrations are human anatomical drawings, including one contrasting facial features and skulls of different human races. The introduction to the encyclopedia is also included
A Redox-Relay Heck Approach to Substituted Tetrahydrofurans
No full textAn operationally simple and efficient strategy for the synthesis of substituted tetrahydrofurans from readily available cis-butene-1,4-diol is described. A redox-relay Heck reaction is used to rapidly access cyclic hemiacetals that can be directly reduced to afford the corresponding 3-aryl tetrahydrofuran. Furthermore, the hemiacetals can also serve as precursors to a range of disubstituted tetrahydrofurans, including the calyxolane natural products
Novel medium ring sized estradiol derivatives by intramolecular heck reactions
No full textNew steroids with a seven-, eight- or nine-membered D-ring have been synthesized from a D-seco-estrone derivative by a Grignard and an intramolecular Heck reactio
Regioirregular and catalytic Mizoroki-Heck reactions
No full text[EN] The palladium-catalysed cross-coupling reaction between alkenes and aryl halides (the Mizoroki-Heck reaction) is a powerful methodology to construct new carbon-carbon bonds. However, the success of this reaction is in part hampered by an extremely marked regioselectivity on the double bond, which dictates that electron-poor alkenes react exclusively on the beta-carbon. Here, we show that ligand-free, few-atom palladium clusters in solution catalyse the alpha-selective intramolecular Mizoroki-Heck coupling of iodoaryl cinnamates, and mechanistic studies support the formation of a sterically encumbered cinnamate-palladium cluster intermediate. Following this rationale, the alpha-selective intermolecular coupling of aryl iodides with styrenes is also achieved with palladium clusters encapsulated within fine-tuned and sterically restricted zeolite cavities to produce 1,1-bisarylethylenes, which are further engaged with aryl halides by a metal-free photoredox-catalysed coupling. These ligand-free methodologies significantly expand the chemical space of the Mizoroki-Heck coupling.This work was supported by MINECO (Spain, projects CTQ 2017-86735-P, PID2019-105391GB-C22 and MAT2017-82288-C2-1-P, Severo Ochoa programme SEV-2016-0683 and the Juan de la Cierva programme). F.G.-P. and R.G. thank ITQ for the concession of a contract. J.O.-M. acknowledges the Juan de la Cierva programme for the concession of a contract, and R.P.-R. and J.C.-S. thank the Plan GenT programme (CIDEGENT/2018/044) funded by Generalitat Valenciana. HR STEM measurements were performed at DME-UCA in Cadiz University, with financial support from FEDER/MINECO (PID2019-110018GA-I00 and PID2019-107578GA-I00). We acknowledge ALBA Synchrotron for allocating beamtime and CL AE SS beamline staff for their technical support during our experiment.Garnes-Portoles, F.; Greco, R.; Oliver-Meseguer, J.; Castellanos-Soriano, J.; Jiménez Molero, MC.; Lopez-Haro, M.; Hernández-Garrido, JC.... (2021). Regioirregular and catalytic Mizoroki-Heck reactions. Nature Catalysis. 4(4):293-303. https://doi.org/10.1038/s41929-021-00592-3S29330344Phan, N. T. S., Van Der Sluys, M. & Jones, C. W. On the nature of the active species in palladium catalysed Mizoroki–Heck and Suzuki–Miyaura couplings—homogeneous or heterogeneous catalysis, a critical review. Adv. Synth. Catal. 348, 609–679 (2006).Mo, J. & Xiao, J. The Heck reaction of electron-rich olefins with regiocontrol by hydrogen-bond donors. Angew. Chem. Int. Ed. 45, 4152–4157 (2006).Wucher, P. et al. Breaking the regioselectivity rule for acrylate insertion in the Mizoroki–Heck reaction. Proc. Natl Acad. Sci. USA 108, 8955–8959 (2011).Barluenga, J., Moriel, P., Valdés, C. & Aznar, F. N. Tosylhydrazones as reagents for cross-coupling reactions: a route to polysubstituted olefins. Angew. Chem. Int. Ed. 46, 5587–5590 (2007).Zou, Y. et al. Selective arylation and vinylation at the α position of vinylarenes. Chem. Eur. J. 19, 3504–3511 (2013).Tang, J., Hackenberger, D. & Goossen, L. J. Branched arylalkenes from cinnamates: selectivity inversion in Heck reactions by carboxylates as deciduous directing groups. Angew. Chem. Int. Ed. 55, 11296–11299 (2016).Sullivan, R. J., Freure, G. P. R. & Newman, S. G. Overcoming scope limitations in cross-coupling of diazo nucleophiles by manipulating catalyst speciation and using flow diazo generation. ACS Catal. 9, 5623–5630 (2019).Nakashima, Y., Hirata, G., Sheppard, T. D. & Nishikata, T. The Mizoroki–Heck reaction with internal olefins: reactivities and stereoselectivities. Asian J. Org. Chem. 9, 480–491 (2020).Torborg, C. & Beller, M. Recent applications of palladium-catalysed coupling reactions in the pharmaceutical, agrochemical and fine chemical industries. Adv. Synth. Catal. 351, 3027–3043 (2009).Dounay, A. B. & Overman, L. E. The asymmetric intramolecular Heck reaction in natural product total synthesis. Chem. Rev. 103, 2945–2963 (2003).Tsvelikhovsky, D. & Buchwald, S. L. Synthesis of heterocycles via Pd-ligand controlled cyclization of 2-chloro-N-(2-vinyl)aniline: preparation of carbazoles, indoles, dibenzazepines and acridines. J. Am. Chem. Soc. 132, 14048–14051 (2010).Wu, X.-F., Anbarasan, P., Neumann, H. & Beller, M. From noble metal to Nobel prize: palladium-catalysed coupling reactions as key methods in organic synthesis. Angew. Chem. Int. Ed. 49, 9047–9050 (2010).Beletskaya, I. P. & Cheprakov, A. V. The Heck reaction as a sharpening stone of palladium catalysis. Chem. Rev. 100, 3009–3066 (2000).Weng, S.-S., Ke, C.-S., Chen, F.-K., Lyu, Y.-F. & Lin, G.-Y. Transesterification catalysed by iron(iii) β-diketonate species. Tetrahedron 67, 1640–1648 (2011).Nájera, C. Oxime-derived palladacycles: applications in catalysis. ChemCatChem 8, 1865–1881 (2016).Leyva-Pérez, A., Oliver-Meseguer, J., Rubio-Marqués, P. & Corma, A. Water-stabilized three- and four-atom palladium clusters as highly active catalytic species in ligand-free C–C cross-coupling reactions. Angew. Chem. Int. Ed. 52, 11554–11559 (2013).Zhu, F., Li, Y., Wang, Z. & Wu, X.-F. Iridium-catalysed carbonylative synthesis of chromenones from simple phenols and internal alkynes at atmospheric pressure. Angew. Chem. Int. Ed. 55, 14151–14154 (2016).Li, X. et al. Palladium-catalysed enantioselective intramolecular dearomative Heck reaction. J. Am. Chem. Soc. 140, 13945–13951 (2018).Fernández, E. et al. Base-controlled Heck, Suzuki and Sonogashira reactions catalysed by ligand-free platinum or palladium single atom and sub-nanometer clusters. J. Am. Chem. Soc. 141, 1928–1940 (2019).Sperger, T., Stirner, C. K. & Schoenebeck, F. Bench-stable and recoverable palladium(i) dimer as an efficient catalyst for Heck cross-coupling. Synthesis 49, 115–120 (2017).Fortea-Pérez, F. R. et al. The MOF-driven synthesis of supported palladium clusters with catalytic activity for carbene-mediated chemistry. Nat. Mater. 16, 760–766 (2017).von Schenck, H., Åkermark, B. & Svensson, M. Electronic control of the regiochemistry in the Heck reaction. J. Am. Chem. Soc. 125, 3503–3508 (2003).Deeth, R. J., Smith, A. & Brown, J. M. Electronic control of the regiochemistry in palladium-phosphine catalysed intermolecular Heck reactions. J. Am. Chem. Soc. 126, 7144–7151 (2004).Djakovitch, L. & Koehler, K. Heck reaction catalysed by Pd-modified zeolites. J. Am. Chem. Soc. 123, 5990–5999 (2001).Dams, M. et al. Pd-zeolites as heterogeneous catalysts in Heck chemistry. J. Catal. 209, 225–236 (2002).Marqués, P., Rivero-Crespo, M. A., Leyva-Pérez, A. & Corma, A. Well-defined noble metal single sites in zeolites as an alternative to catalysis by insoluble metal salts. J. Am. Chem. Soc. 137, 11832–11837 (2015).Corma, A., García, H., Leyva, A. & Primo, A. Basic zeolites containing palladium as bifunctional heterogeneous catalysts for the Heck reaction. Appl. Catal. A 247, 41–49 (2003).Sun, T., Seff, K., Heo, N. H. & Petranovskii, V. P. A cationic cesium continuum in zeolite X. Science 259, 495–497 (1993).Agostini, G. et al. Preparation of supported Pd catalysts: from the Pd precursor solution to the deposited Pd2+ phase. Langmuir 26, 11204–11211 (2010).Cerrillo, J. L. et al. Nature and evolution of Pd catalysts supported on activated carbon fibers during the catalytic reduction of bromate in water. Catal. Sci. Technol. 10, 3646–3653 (2020).Liu, L. & Corma, A. Metal catalysts for heterogeneous catalysis: from single atoms to nanoclusters and nanoparticles. Chem. Rev. 118, 4981–5079 (2018).Liu, L. et al. Regioselective generation and reactivity control of subnanometric platinum clusters in zeolites for high-temperature catalysis. Nat. Mater. 18, 866–873 (2019).Liu, L. et al. Structural modulation and direct measurement of subnanometric bimetallic PtSn clusters confined in zeolites. Nat. Catal. 3, 628–638 (2020).Liu, L. et al. Tutorial: structural characterization of isolated metal atoms and subnanometric metal clusters in zeolites. Nat. Protoc. https://doi.org/10.1038/s41596-020-0366-9 (2020).Li, P. et al. Explaining the influence of the introduced base sites into alkali oxide modified CsX towards side-chain alkylation of toluene with methanol. RSC Adv. 9, 13234–13242 (2019).Concepcion-Heydorn, P. et al. Structural and catalytic properties of sodium and cesium exchanged X and Y zeolites, and germanium substituted X zeolite. J. Mol. Catal. A 162, 227–246 (2000).Seo, D.-W., Rahma, S. T., Reddy, B. M. & Parka, S.-E. Carbon dioxide assisted toluene side-chain alkylation with methanol over Cs-X zeolite catalyst. J. CO2 Util. 26, 254–261 (2018).Rivero-Crespo, M. Á. et al. Intermolecular carbonyl-olefin metathesis with vinyl ethers catalysed by homogeneous and solid acids in flow. Angew. Chem. Int. Ed. 59, 3846–3849 (2020).Kashani, S. K., Jessiman, J. E. & Newman, S. G. Exploring homogeneous conditions for mild Buchwald–Hartwig amination in batch and flow. Org. Process Res. Dev. https://doi.org/10.1021/acs.oprd.0c00018 (2020).Alami, M., Liron, F., Gervais, M., Peyrat, J.-F. & Brion, J.-D. Ortho substituents direct regioselective addition of tributyltin hydride to unsymmetrical diaryl (or heteroaryl) alkynes: an efficient route to stannylated stilbene derivatives. Angew. Chem. Int. Ed. 41, 1578–1580 (2002).Onuigbo, L., Raviola, C., Di Fonzo, A., Protti, S. & Fagnoni, M. Sunlight-driven synthesis of triarylethylenes (TAEs) via metal-free Mizoroki–Heck-type coupling. Eur. J. Org. Chem. 38, 5297–5303 (2018).Wang, H., Gao, Y., Zhou, C. & Li, G. Visible-light-driven reductive carboarylation of styrenes with CO2 and aryl halides. J. Am. Chem. Soc. 142, 8122–8129 (2020).Zuo, Z. & MacMillan, D. W. C. Decarboxylative arylation of α-amino acids via photoredox catalysis: a one-step conversion of biomass to drug pharmacophore. J. Am. Chem. Soc. 136, 5257–5260 (2014).Bardagi, J. I., Ghosh, I., Schmalzbauer, M., Ghosh, T. & König, B. Anthraquinones as photoredox catalysts for the reductive activation of aryl halides. Eur. J. Org. Chem. 1, 34–40 (2018).Majek, M., Faltermeier, U., Dick, B., Pérez-Ruiz, R. & Jacobi von Wangelin, A. Application of visible-to-UV photon upconversion to photoredox catalysis: the activation of aryl bromides. Chem. Eur. J. 21, 15496–15501 (2015).López-Calixto, C. G., Liras, M., de la Peña O’Shea, V. A. & Pérez-Ruiz, R. Synchronized biphotonic process triggering C–C coupling catalytic reactions. Appl. Catal. B 237, 18–23 (2018).Martínez-Gualda, A. M. et al. Chromoselective access to Z- or E-allylated amines and heterocycles by a photocatalytic allylation reaction. Nat. Commun. 10, 2634 (2019).Yang, J. et al. Direct synthesis of adipic acid esters via palladium catalysed carbonylation of 1,3-dienes. Science 366, 1514–1517 (2019).Uehling, M. R., King, R. P., Krska, S. W., Cernak, T. & Buchwald, S. L. Pharmaceutical diversification via palladium oxidative addition complexes. Science 363, 405–408 (2019).Ross, S. P., Rahman, A. A. & Sigman, M. S. Development and mechanistic interrogation of interrupted chain-walking in the enantioselective relay Heck reaction. J. Am. Chem. Soc. 142, 10516–10525 (2020)
Low-Temperature Heck Reactions of Axially Chiral o-Iodoacrylanilides Occur with Chirality Transfer: Implications for Catalytic Asymmetric Heck Reactions.
No full textLow-temperature Heck reactions of chiral o-iodoacrylanilides with achiral palladium catalysts occur with efficient transfer of chirality from the chiral axis of the precursor to the new stereocenter of the product. The results suggest that the primary stereocontrolling step in asymmetric Heck reactions is a dynamic kinetic resolution (oxidative addition to the C−I) bond and not a face selective reaction (complexation or insertion to the alkene)
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