1,721,023 research outputs found
Total Synthesis Of (±)-homopumiliotoxin 223g
No full textThe total synthesis of (±)-homopumiliotoxin 223G was achieved in six steps and 14% yield through the addition of 5-methyl-2-triisopropylsilyoxyfuran (3) to the N-acyliminium ion derived from N-Cbz 2-methoxypiperidine featuring bicyclic lactam 9b as the key intermediate. © 2001 Elsevier Science Ltd. All rights reserved.424069997001Daly, J.W., Garrafo, H.M., Spande, T.F., (1993) The Alkaloids, p. 85. , Cordell, G. A., Ed.San Diego, CA: Academic PressDaly, J.W., (1998) J. Nat. Prod., 61, p. 162Jones, T.H., Gorman, J.S.T., Snelling, R.R., Delabie, J.H.C., Blum, M.S., Garraffo, H.M., Jain, P., Spande, T.F., (1999) J. Chem. Ecol., 25, p. 1179Aoyagi, S., Hasegawa, Y., Hirashima, S., Kibayashi, C., (1998) Tetrahedron Lett., 39, p. 2149Kibayashi, C., Aoyagi, S., Wang, T.C., Saito, K., Daly, J.W., Spande, T.F., (2000) J. Nat. Prod., 63, p. 1157De Oliveira, M.C.F., Santos, L.S., Pilli, R.A., (2001) Tetrahedron Lett., 42, p. 6995Santos, L.S., Pilli, R.A., (2000) 22nd IUPAC International Symposium on the Chemistry of Natural Products, , OSA-12, São Carlos, SP, BrazilArend, M., Westermann, B., Risch, N., (1998) Angew. Chem., Int. Ed. Engl., 37, p. 1045Nasman, H., Pensar, K.G., (1985) Synthesis, p. 786Martin, S.F., Bur, S.K., (1999) Tetrahedron, 55, p. 8905Morimoto, Y., Nishida, K., Hayashi, Y., Shirahama, H., (1993) Tetrahedron Lett., 34, p. 5773noteFox, D.N.A., Lathbury, D., Mahon, M.F., Molloy, K.C., Gallagher, T., (1991) J. Am. Chem. Soc., 113, p. 2652Stork, G., Shiner, C.S., Winkler, J.D., (1982) J. Am. Chem. Soc., 104, p. 310Crabb, T.A., Newton, R.F., Jackson, D., (1971) Chem. Rev., 71, p. 109Thornton, E.R., Stormes, M.N., (1991) J. Org. Chem., 56, p. 2489Tokuyama, T., Nishimori, N., Shimada, A., (1987) Tetrahedron, 43, p. 643Yoon, N.M., Brown, H.C., (1968) J. Am. Chem. Soc., 90, p. 292
Asymmetric Total Synthesis And Antiproliferative Activity Of Goniothalamin Oxide Isomers
No full textGoniothalamin oxide (1) is a styryl lactone which was isolated from bark and leaves of several Goniothalamus species. This natural product has some interesting biological properties such as larvicidal and tripanocidal activities. However, no studies on the antiproliferative profile of goniothalamin oxide (1) and its stereoisomers have been reported yet. Here, goniothalamin epoxide (1), isogoniothalamin epoxide (2) and their enantiomers were prepared via epoxidation of (R)-and (S)-goniothalamin (4). A 3:2 molar ratio in favor of goniothalamin oxide (1) and ent-1 was observed from (R)- and (S)-4, respectively, when 3-chloroperbenzoic acid (mCPBA) was employed while an increase to 6:1 molar ratio was achieved with (S,S)-Jacobsen's catalyst. Antiproliferative activity of these epoxides revealed that ent-isogoniothalamin oxide (ent-2) was the most active against the eight cancer cell lines studied. These results indicate that 6S, 7R and 8R absolute configurations are beneficial for the activity of these epoxides. © 2009.3725256Blázquez, M.A., Bermejo, A., Zafra-Polo, M.C., Cortes, D., (1999) Phytochem. Anal., 10, pp. 161-170de Fátima, A., Modolo, L.V., Conegero, L.S., Pilli, R.A., Ferreira, C.V., Kohn, L.K., de Carvalho, J.E., (2006) Curr. Med. Chem., 13, pp. 3371-3384de Fátima, A., Zambuzzi, W.F., Modolo, L.V., Tarsitano, C.A.B., Gadelha, F.R., Hyslop, S., de Carvalho, J.E., Pilli, R.A., (2008) Chem. Biol. Int., 176, pp. 143-150Martins, C.V.B., de Resende, M.A., Magalhães, T.F.F., Lima, B.H.S., Watanabe, G.A., Ruiz, A.L.T.G., de Carvalho, J.E., de Fátima, A., (2008) Lett. Drug. Des. Discov., 5, pp. 74-78Sam, T.W., Sew-Yeu, C., Matsjeh, S., Gan, E.K., Razak, D., Mohamed, A.L., (1987) Tetrahedron Lett., 28, pp. 2541-2544Lan, Y.H., Chang, F.R., Yu, J.H., Yang, Y.L., Chang, Y.L., Lee, S.J., Wu, Y.C., (2003) J. Nat. Prod., 66, pp. 487-490Goh, S.H., Ee, G.C.L., Chuah, C.H., Wei, C., (1995) Aust. J. Chem., 48, pp. 199-205de Fátima, A., Marquissolo, C., de Albuquerque, S., Carraro-Abrahão, A.A., Pilli, R.A., (2006) Eur. J. Med. Chem., 41, pp. 1210-1213Blagosklonny, M.V., (2005) Cell Cycle, 4, pp. 1518-1521Weisz, B., Meirow, D., Schiff, E., Lishner, M., (2004) Expert Rev. Anticancer Ther., 4, pp. 889-902Fuganti, C., Pedrocchi-Fantoni, G., Sarra, S., Servi, S., (1994) Tetrahedron: Asymmetry, 5, pp. 1135-1138Surivet, J.-P., Vatèle, J.-M., (1999) Tetrahedron, 55, pp. 13011-13028Peng, X., Li, A., Shen, H., Wu, T., Pan, X., (2002) J. Chem. Res.(S), pp. 330-332Pospíšil, J., Markó, I.E., (2006) Tetrahedron Lett., 47, pp. 5933-5937Bose, D.S., Reddy, A.V.N., Srikanth, B., (2008) Synthesis, pp. 2323-2326Monks, A., Scudeiro, D., Skehan, P., Shoemaker, R., Paull, K., Vistica, D., Hose, C., Boyd, M., (1991) J. Nat. Can. Inst., 83, pp. 757-766de Fátima, A., Pilli, R.A., (2003) Tetrahedron Lett., 44, pp. 8721-8724de Fátima, A., Pilli, R.A., (2003) Arkivoc, 10, pp. 118-126de Fátima, A., Kohn, L.K., Antônio, M.A., de Carvalho, J.E., Pilli, R.A., (2004) Bioorg. Med. Chem., 12, pp. 5437-5442de Fátima, A., Kohn, L.K., de Carvalho, J.E., Pilli, R.A., (2006) Bioorg. Med. Chem., 14, pp. 622-631Jacobsen, E.N., Zhang, W., Muci, A.R., Ecker, J.R., Deng, L., (1991) J. Am. Chem. Soc., 113, pp. 7063-7064Hosoya, N., Irie, R., Katsuki, T., (1993) Synlett, pp. 261-26
Synthesis Of Methoxylated Goniothalamin, Aza-goniothalamin And γ-pyrones And Their In Vitro Evaluation Against Human Cancer Cells
No full textThe present work describes the preparation of three novel series of compounds based on the structure of goniothalamin, a natural styryl lactone which has been found to display cytotoxic and antiproliferative activities against a variety of cancer cell lines. A focused library of 29 novel goniothalamin analogues was prepared and evaluated against seven human cancer cell lines. While the γ-pyrones and the aza-goniothalamin analogues were less potent than the lead compound, 2,4-dimethoxy analogue 88 has shown to be more potent in vitro than goniothalamin against all cancer cell lines evaluated. Furthermore, it was more potent than doxorubicin against NCI-ADR/RES, OVCAR-03 and HT-29 while being less toxic to human keratinocytes (HaCat). The 3,5-dimethoxy analogue 90 and 2,4,5-trimethoxy analogue 92 also displayed promising antiproliferative activity when compared to goniothalamin (1). These results provide new elements for the design and synthesis of novel representatives of this family of natural compounds. © 2012 Elsevier Ltd. All rights reserved.201136353651Newman, D.J., Cragg, G.M.J., (2012) Nat. Prod., 75, p. 311Harvey, A.L., (2008) Drug Discovery Today, 13, p. 894De Fátima, A., Kohn, L.K., Antonio, M.A., De Carvalho, J.E., Pilli, R.A., (2005) Bioorg. Med. Chem., 13, p. 2927De Fátima, A., Kohn, L.K., De Carvalho, J.E., Pilli, R.A., (2006) Bioorg. Med. Chem., 14, p. 622Chiu, C.-C., Liu, P.-L., Huang, K.-J., Wang, H.-M., Chang, K.-F., Chou, C.-K., Chang, F.-R., Wu, Y.-C., (2011) Agric. J. Food Chem., 59, p. 4288. , For antiproliferative activities against lung and liver cell lines, seeAl-Qubaisi, M., Rozita, R., Yeap, S.-K., Omar, A.-R., Ali, A.-M., Alitheen, N.B., (2011) Molecules, 16, p. 2944Ali, A., MacKeen, M.M., Hamid, M., Aun, Q.B., Zauyah, Y., Azimahtol, H.L.P., Kawazu, K., (1997) Planta Med., 63, p. 81Khan, M.R., Komine, K., Omoloso, A.D., (1999) Phar. 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Novel Supramolecular Palladium Catalyst For The Asymmetric Reduction Of Imines In Aqueous Media
No full textA novel approach to the asymmetric reduction of dihydro-β-carboline derivatives to the corresponding tetrahydro-β-carbolines is described based on the supramolecular lyophilized complex formed from β-cyclodextrin/ imines as an enzyme mimetic and palladium hydride as the reducing agent. The methodology allowed us to develop a short and efficient preparation of (R)-harmicine and (R)-deplancheine alkaloids in high overall yields and ee of 89 and 90%, respectively. © 2009 American Chemical Society.111532383241Surendra, K., Krishnaveni, N.S., Sridhar, R., Rao, K.R., (2006) J. Org. Chem, 71, pp. 5819-5821Santos, L.S., Fernandes, S.A., Pilli, R.A., Marsaioli, A.J., (2003) Tetrahedron: Asymmetry, 14, pp. 2515-2519Shankaraiah, N., da Silva, W.A., Andrade, C.K.Z., Santos, L.S., (2008) Tetrahedron Lett, 49, pp. 4289-4291Fornasier, R., Reniera, F., Scrimin, P., Tonellato, U., (1985) J. Org. Chem, 50, pp. 3209-3211Kawajiri, Y., Motohashi, N., (1989) J. Chem. Soc., Chem. Commun, pp. 1336-1337Sakuraba, H., Inomata, N., Tanaka, Y., (1989) J. Org. Chem, 54, pp. 3482-3484Uematsu, N., Fujii, A., Hashiguchi, S., Ikariya, T., Noyori, R., (1996) J. Am. Chem. Soc, 118, pp. 4916-4917Yamakawa, M., Ito, H., Noyori, R., (2000) J. Am. Chem. Soc, 122, pp. 1466-1478Mao, J.M., Baker, D.C., (1999) Org. Lett, 1, pp. 841-843James, B.R., (1997) Catal. Today, 37, pp. 209-221Kobayashi, S., Ishitani, H., (1999) Chem. Rev, 99, pp. 1069-1094Shankaraiah, N., Santos, L.S., (2009) Tetrahedron Lett, 50, pp. 520-523. , For other applications of the Noyori hydrogenation toward alkaloid compounds, see: aSantos, L.S., Pilli, R.A., Rawal, R.H., (2004) J. Org. Chem, 69, pp. 1283-1289Kaldor, I., Feldman, P.L., Mook, R.A., Ray, J.A., Samano, V., Sefler, A.M., Thompson, J.B., Boras, E.E., (2001) J. Org. Chem, 66, pp. 3495-3501Tietze, L.F., Zhou, Y.F., Topken, E., (2000) Eur. J. Org. Chem, pp. 2247-2252Meuzelaar, G. J.van, VlietMaat, L.Sheldon, R. A. Eur. J. Org. Chem. 1999, 2315-2321Schlatter, A., Woggon, W.D., (2008) Adv. Synth. Catal, 350, pp. 995-1000Schlatter, A., Kundu, M.K., Woggon, W.D., (2004) Angew. Chem., Int. Ed, 43, pp. 6731-6734Kam, T.S., Sim, K.M., (1998) Phytochemistry, 47, pp. 145-147Itoh, T., Miyazaki, M., Nagata, K., Yokoya, M., Nakamura, S., Ohsawa, A., (2002) Heterocycles, 58, pp. 115-118Besselièvre, R., Cosson, J.P., Das, B.C., Husson, H.P., (1980) Tetrahedron Lett, 121, pp. 63-66Petitfrere-Auvray, N., Vercauteren, J., Massiot, G., Lukacs, G., Sevente, L., Le Men-Olivier, L., Richard, B., Jacquier, M.J., (1981) Phytochemistry, 23, pp. 1987-1990Guillaume, D., Morfaux, A.M., Richard, B., Massiot, G., Le Men-Olivier, L., Pusset, J., Sevenet, T., (1984) Phytochemistry, 23, pp. 2407-2408Cherif, A., Massiot, G., Le Men-Olivier, L., Pusset, J., Labarre, S., (1989) Phytochemistry, 28, pp. 667-670Robert, G.M.T., Ahond, A., Poupat, C., Potier, P., Jolles, C., Jousselin, A., Jacquemin, H., (1983) J. Nat. Prod, 46, pp. 694-707Meyers, A.I., Sohda, T., Loewe, M.F., (1986) J. Org. Chem, 51, pp. 3108-3112Takasu, K., Nishida, N., Tomimura, A., Ihara, M., (2005) J. Org. Chem, 70, pp. 3957-3962. , For asymmetric syntheses of deplancheine, see: aSydorenko, N., Zificsak, C.A., Gerasyuto, A.I., Hsung, R.P., (2005) Org. Biomol. Chem, 3, pp. 2140-2144Allin, S.M., Thomas, C.I., Doyle, K., Elsegood, M.R.J., (2005) J. Org. Chem, 70, pp. 357-359Lounasmaa, M., Karinen, K., Tovanen, A., (1997) Heterocycles, 45, pp. 1397-1404Tirkkonen, B., Miettinen, J., Salo, J., Jokela, R., Lounasmaa, M., (1994) Tetrahedron, 50, pp. 3537-3556Mandai, S.B., Giri, V.S., Sabeena, M.S., Pakrashi, S.C., (1988) J. Org. Chem, 53, pp. 4236-4241Santos, L.S., Pilli, R.A., (2001) Tetrahedron Lett, 42, pp. 6999-7001Santos, L.S., Pilli, R.A., (2003) J. Braz. Chem. Soc, 14, pp. 982-99
Trypanocidal Activity Of 5,6-dihydropyran-2-ones Against free Trypomastigotes Forms Of trypanosoma cruzi
No full textSixteen 5,6-dihydro-2H-pyran-2-ones were evaluated in in vitro assay against trypomastigotes forms of Trypanosoma cruzi, the causative agent of Chagas' disease. A structure-activity relationship study (SAR) allowed us to establish the relevant structural features for the trypanocidal activity of goniothalamin analogues against T. cruzi. In fact, non-natural form of goniothalamin (ent-1) was threefold more potent than the natural one (1). In addition, we have identified analogues 9 and 10 (both displaying S configuration) as the highest potent compounds against T. cruzi with IC50 = 0.12 and 0.09 mM (IC50 value for crystal violet was 0.08 mM) whereas significantly lower toxicities were observed when these compounds were evaluated under LLC-MK2 lineage cells (1.38 and 4.89 mM, respectively). In addition, epoxides derivatives 12 and ent-12 were shown to be more potent than the corresponding stereoisomers 2 and ent-2 and non-natural argentilactone (ent-3, IC50 = 0.47 mM) was twofold more potent than natural argentilactone (3, IC50 = 0.94 mM). © 2006 Elsevier Masson SAS. All rights reserved.411012101213Hoare, C.A., Wallace, F.G., (1996) Nature, 244, pp. 69-70Andrade, Z.A., (1999) Mem. Inst. Oswaldo Cruz, 94, pp. 71-80Krauth-Siegel, R.L., Bauer, H., Schirmer, R.H., (2005) Angew. Chem. Int. Ed. Engl., 44, pp. 690-715Canesin, M.F., Barreto, A.C.P., (1997) Rev. Soc. Card. Est, São Paulo, 7, pp. 233-239Coura, J.R., Castro, S.L., (2002) Mem. Inst. Oswaldo Cruz, 97, pp. 3-24Cerecetto, H., Maio, R.D., Gonzales, M., Risso, M., Sagrera, G., Seoane, G., Denicola, A., Basombrio, M.A., (2000) Eur. J. Med. Chem., 35, pp. 343-350Aguirrea, G., Boiania, L., Cerecetto, H., Fernándeza, M., Gonzáleza, M., Denicolab, A., Oteroc, L., Faundez, M., (2004) Bioorg. Med. Chem., 12, pp. 4885-4893Aguirrea, G., Cabreraa, E., Cerecetto, H., Maioa, R.D., Gonzáleza, M., Seoanea, G., Duffautb, A., Martínez-Merino, V., (2004) Eur. J. Med. Chem., 39, pp. 421-431Molfetta, F.A., Bruni, A.T., Honorio, K.M., da Silva, A.B.F., (2004) Eur. J. Med. Chem., 40, pp. 329-338Keiser, J., Stich, A., Burri, C., (2001) Trends Parasitol., 17, pp. 42-49Lee, K.-H., (2004) J. Nat. Prod., 67, pp. 273-283Butler, M.S., (2004) J. Nat. Prod., 67, pp. 2141-2153Clardy, J., Walsh, C., (2004) Nature, 432, pp. 829-837Blázquez, M.A., Bermejo, A., Zafra-Polo, M.C., Cortes, D., (1999) Phytochem. Anal., 10, pp. 161-170Meenakshii, N., Lee, A., Azimahtol, H.L.P., Hasidah, S., (2000) Malays, Appl. Biol., 29, pp. 121-126de Fátima, A., Kohn, L.K., de Carvalho, J.E., Pilli, R.A., (2006) Bioorg. Med. Chem., 14, pp. 622-631Mosaddik, M.A., Hauqe, M.E., (2003) Phytotherapy Res., 17, pp. 1155-1157Kabir, K.E., Khan, A.R., Mosaddik, M.A., (2003) Appl. Ent., 127, pp. 112-115Mosaddik, M.A., Hauqe, M.E., Rashid, M.A., (2000) Biochem. Systemat. Ecol., 28, pp. 1039-1040Sam, T.W., Sew-Yeu, C., Matsjeh, S., Gan, E.K., Razak, D., Mohamed, A.L., (1987) Tetrahedron Lett., 28, pp. 2541-2544Lan, Y.H., Chang, F.R., Yu, J.H., Yang, Y.L., Chang, Y.L., Lee, S.J., Wu, Y.C., (2003) J. Nat. Prod., 66, pp. 487-490Goh, S.H., Ee, G.C.L., Chuah, C.H., Wei, C., Mak, T.C.W., (1995) Aust. J. Chem., 48, pp. 199-205Priestap, H.A., Bonafede, J.D., Ruveda, E.A., (1977) Phytochemistry, 16, pp. 1579-1582Matsuda, M., Endo, Y., Fushiya, S., Endo, T., Nozoe, S., (1994) Heterocycles, 38, pp. 1229-1232Waechter, A.I., Ferreira, M.E., Fournet, A., Arias, A.R., Nakayama, H., Torres, S., Hocquemiller, R., Cave, A., (1997) Planta Med., 63, pp. 433-435Carmona, D., Sáez, J., Granados, H., Pérez, E., Blair, S., Angulo, A., Figadere, B., (2003) Nat. Prod. Res., 17, pp. 275-280de Fátima, A., Pilli, R.A., (2003) Arkivoc, 10, pp. 118-126de Fátima, A., Pilli, R.A., (2003) Tetrahedron Lett., 44, pp. 8721-8724de Fátima, A., Kohn, L.K., Antonio, M.A., de Carvalho, J.E., Pilli, R.A., (2004) Bioorg. Med. Chem., 12, pp. 5437-5442de Fátima, A., Kohn, L.K., Antonio, M.A., de Carvalho, J.E., Pilli, R.A., (2005) Bioorg. Med. Chem., 13, pp. 2927-2933Neto, A.G., da Silva Filho, A.A., Costa, J.M.L.C., Vinholis, A.H.C., Souza, G.H.B., Cunha, W.R., Silva, M.L.A.E., Bastos, J.K., (2004) Phytomed., 11, pp. 622-665Ambrozin, A.R.P., Mafezoli, J., Vieira, P.C., Fernandes, J.B., da Silva, M.F.G.F., Ellena, J.A., Albuquerque, S., (2005) J. Braz. Chem. Soc., 16, pp. 434-439de Souza, V.A., da Silva, R., Pereira, A.C., Royo, V.A., Saraiva, J., Montanheiro, M., de Souza, G.H.B., Silva, M.L.A., (2005) Bioorg. Med. Chem. Lett., 15, pp. 303-307Mosmann, T., (1983) J. Immunol. Methods, 65, pp. 55-6
Total Synthesis And Structural Elucidation Of Natural Products: (-)-delactonmycin, (+)-plumerinine, And (-)-parvistemoamide
No full textSynthetic studies that established the relative configuration of (-)-delactonmycin, a polyketide with inhibitory activity against HIV-1 Rev protein, and our efforts toward the structural elucidation of the alkaloids (+)-plumerinine, isolated from P. rubra, and (-)-parvistemoamide, isolated from S. parviflora, are discussed. © 2005 IUPAC.77711531160Lichtenthaler, F.W., (2002) Eur. J. Org. Chem., 4095Nicolaou, K.C., Sorensen, E.J., (1996) Classic in Total Synthesis, , Wiley-VCH, WeinheimNicolaou, K.C., Snyder, S.A., (2003) Classics in Total Synthesis II. Targets, Strategies, Methods, , Wiley-VCH, WeinheimNicolaou, K.C., Baran, P.S., (2002) Angew. Chem., Int. Ed., 41, p. 2679Wender, P.A., Baryza, J.L., Brenner, S.E., Clarke, M.O., Gamber, G.G., Horan, J.C., Jessop, T.C., Williams, T.J., (2003) Pure Appl. Chem., 75, p. 143Pilli, R.A., Murta, M.M., (1993) J. Org. Chem., 58, p. 338Pilli, R.A., De Andrade, C.K.Z., De Souto, C.R.O., De Meijere, A., (1998) J. Org. Chem., 63, p. 7811Pilli, R.A., Victor, M.M., (1998) Tetrahedron Lett., 39, p. 4421Pilli, R.A., Victor, M.M., De Meijere, A., (2000) J. Org. Chem., 65, p. 5910Pilli, R.A., Dias, L.C., Maldaner, A.O., (1995) J. Org. Chem., 60, p. 717Pilli, R.A., Russowsky, D., (1996) J. Org. Chem., 61, p. 3187Pilli, R.A., Rosso, G.B., (2004) Science of Synthesis, 27, p. 375. , Houben-Weyl Methods of Molecular Transformations, A. Padwa (Ed.), Georg Thieme VerlagCorrêa Jr., I.R., Pilli, R.A., (2003) Angew. Chem., Int. Ed., 42, p. 3017Maldaner, A.O., Pilli, R.A., (2004) Synlett, p. 1343Hamamoto, T., Gunji, S., Tsuji, H., Beppu, T., (1983) J. Antibiot., 36, p. 639Hamamoto, T., Seto, H., Beppu, T., (1983) J. Antibiot., 36, p. 646Funaishi, K., Kawamura, K., Sugiura, Y., Nakahori, N., Yoshida, E., Okanishi, M., Umezawa, I., Komiyama, K., (1987) J. Antibiot., 40, p. 778Takamiya, K., Yoshida, E., Takahashi, T., Okura, A., Okanishi, M., Komiyama, K., Umezawa, I., (1988) J. Antibiot., 41, p. 1854Umezawa, I., Komiyama, K., Oka, H., Okada, K., Tomisaka, S., Miyano, T., Takano, S., (1984) J. Antibiot., 37, p. 706Komiyama, K., Okada, K., Oka, H., Tomisaka, S., Miyano, T., Funayama, S., Umezawa, I., (1985) J. Antibiot., 38, p. 220Komiyama, K., Okada, K., Hirokawa, Y., Masuda, K., Tomisaka, S., Umezawa, I., (1985) J. Antibiot., 38, p. 224Kalesse, M., Christmann, M., Synthesis, 981, p. 2002Paterson, I., Arnott, E.A., (1998) Tetrahedron Lett., 39, p. 7185Tamaru, Y., Ochiai, H., Nakamura, T., Tsubaki, K., Yoshida, Z.-I., (1985) Tetrahedron Lett., 26, p. 5559Comins, D.L., Zheng, X.L., Goehring, R.R., (2002) Org. Lett., 4, p. 1611Pilli, R.A., Maldaner, A.O., (1999) Tetrahedron, 55, p. 13321Pilli, R.A., De Oliveira, M.C.F., (2000) Nat. Prod. Rep., 17, p. 117Pilli, R.A., De Oliveira, M.C.F., Rosso, G.B., (2005) The Alkaloids, 62, p. 77. , G. A. Cordell (Ed.) , Academic Press, New YorkMungkornasawakul, P., Pyne, S.G., Jatisatienr, A., Supyen, D., Lie, W., Ung, A.T., Skelton, B.W., White, A.H., (2003) J. Nat. Prod., 66, p. 980Kaltenegger, E., Brem, B., Mereiter, K., Kalchhauser, H., Kählig, H., Hofer, O., Vajrodaya, S., Greger, H., (2003) Phytochemistry, 63, p. 803Lin, W.-H., Xu, R.-S., Zhong, Q.-X., (1991) Acta Chim. Sin., 49, p. 927Xu, R.-S., Tang, Z.-J., Feng, S.-C., Yang, Y.-P., Lin, W.-H., Zhong, Q.-X., Zhong, Y., (1991) Mem. Inst. Oswaldo Cruz, 86 (SUPPL. II), p. 5
Enantioselective Catalytic Allylation And Crotylation Of Aldehydes [alilação E Crotilação Catalítica E Enantiosseletiva De Aldeídos]
No full textThe field of chiral catalysis has experienced explosive growth over the last two decades. By now, many of the classical reactions in organic synthesis can be carried out efficiently in asymmetric manner. As one of the fundamental and powerful C-C bond-forming reactions, enantioselective catalytic allylation (ECA) and crotylation (ECC) of aldehydes has attracted considerable attention. In this article, we present an overview about the importance of chiral Lewis acids and bases in catalytic enantioselective addition of allyl- and crotyl metals to aldehydes and the application of this methodology in the total synthesis of natural and non-natural products.29510091026Wender, P.A., (1993) Organic Synthesis. Theory and Applications, , Hudlicky, T., ed.Jai PressSheldon, R.A., (1997) Chem. Ind., p. 12Sime, J.T., (1999) J. Chem. Educ., 76, p. 1658Yanagisawa, A., (1999) Comprehensive Asymmetric Catalysis, , Jacobsen, E. 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A Novel Asymmetric Reduction Of Dihydro-β-carboline Derivatives Using Calix[6]arene/chiral Amine As A Host Complex
No full textA novel approach to the asymmetric reduction of dihydro-β-carboline derivatives to the corresponding tetrahydro-β-carboline is described based on the supramolecular complex formed from calix[6]arene/chiral amine as an enzyme mimetic and NaBH4 as the reducing agent. © 2003 Elsevier Ltd. All rights reserved.141725152519Santos, L.S., Pilli, R.A., Rawal, V.H., manuscript in preparationBakos, J., Tóth, I., Heil, B., Markó, L., (1985) J. Organomet. Chem., 279, p. 23Kang, G.-J., Cullen, W.R., Fryzuk, M.D., James, B.R., Kutney, J.P., (1988) J. Chem. Soc., Chem. Commun., p. 1466Bakos, J., Orosz, Á., Heil, B., Laghmari, M., Lhoste, P., Sinou, D., (1991) J. Chem. Soc., Chem. Commun., p. 1684Lensink, C., Vries, J.G., (1992) Tetrahedron: Asymmetry, 3, p. 235Burk, M.J., Feaster, J.E., (1992) J. Am. Chem. Soc., 114, p. 6266Vastag, S., Bakos, J., Törös, S., Takach, N.E., King, R.B., Heil, B., Markó, L., (1984) J. Mol. Catal., 22, p. 283Spindler, F., Pugin, B., Blaser, H.-U., (1990) Angew. Chem., Int. Ed., 29, p. 558Ng Cheong Chan, Y., Osborn, J.A., (1990) J. Am. Chem. Soc., 112, p. 9400Morimoto, T., Nakajima, N., Achiwa, K., (1995) Synlett, p. 748Noyori, R., Ohta, M., Hsiao, Y., Kitamura, M., Ohta, T., Takaya, H., (1986) J. Am. Chem. Soc., 108, p. 7117Kitamura, M., Hsiao, Y., Ohta, M., Tsukamoto, M., Ohta, T., Takaya, H., Noyori, R., (1994) J. Org. Chem., 59, p. 297Willoughby, C.A., Buchwald, S.L., (1992) J. Am. Chem. Soc., 114, p. 7562Willoughby, C.A., Buchwald, S.L., (1994) J. Am. Chem. Soc., 116, p. 8952Cho, B.T., Chun, Y.S., (1992) Tetrahedron: Asymmetry, 3, p. 1583Bolm, C., Felder, M., (1994) Synlett, p. 655Uematsu, N., Fujii, A., Hashiguchi, S., Ikariya, T., Noyori, R., (1996) J. Am. Chem. Soc., 118, p. 4916Yamakawa, M., Ito, H., Noyori, R., (2000) J. Am. Chem. Soc., 122, p. 1466Mao, J., Baker, D.C., (1999) Org. Lett., 1, p. 841James, B.R., (1997) Catal. Today, 37, p. 209Kobayashi, S., Ishitani, H., (1999) Chem. Rev., 99, p. 1069Fornasier, R., Reniero, F., Scrimin, P., Tonellato, U., (1985) J. Org. Chem., 50, p. 3209Kawajiri, Y., Motohashi, N., (1989) J. Chem. Soc., Chem. Commun., p. 1336Sakuraba, H., Inomata, N., Tanaka, Y., (1984) J. Org. Chem., 54, p. 3482Breslow, R., (1995) Acc. Chem. Res., 28, p. 146Wenz, G., (1994) Angew. Chem., Int. Ed., 33, p. 803Jones, J.B., (1986) Tetrahedron, 42, p. 3351Schoffers, E., Golebiowski, A., Johnson, C.R., (1996) Tetrahedron, 52, p. 3769Compound 2a was previously used in the synthesis of (+)-arborescidine A, Ref. 1Deratani, A., Renard, E., Djedaïni-Pilard, F., Perly, B., (1997) J. Chem. Soc., Perkin Trans. 2, p. 1517We tried to reduce the amount of NaBH4 employed, but unfortunately the hydrogenation of the corresponding imines 1a-d only proceeded with 7 or more equivalents of the reducing agentTakahashi, K., Hattori, K., (1994) J. Incl. Phenom., 17, p. 1Borges, R.B., Laverde A., Jr., Porto, A.L.M., Marsaioli, A.J., (2000) Spectrosc-Int J., 14, p. 203Laverde A., Jr., Conceição, G.J.A., Queiroz, S.C.N., Fujiwara, F.Y., Marsaioli, A.J., (2002) Magn. Reson. Chem., 40, p. 433Santos, L.S., Pilli, R.A., Rawal, V.H., manuscript in preparationCompound 2c was previously used in the total synthesis of (-)-arborescidine C and D, Ref.
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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