138,732 research outputs found
Synthesis and structure of the tetrameric [Cp V(mu-F)(2)](4) (Cp = C5Me5); Preparation of the imido molybdenum fluoride [(2,6-i-Pr2C6H3N)(2)MoF2]center dot THF and the structural investigation of [(2,6-i-Pr2C6H3N)(6)Mo-4(mu(3)-F)(2)Me-2(mu-O)(4)]
No full textTreating [Cp V(mu-Cl)(2)](3) (Cp = C5Me5) and [(2,6-i-Pr2C6H3N)(2)MoMe2], respectively, with Me3SnF afforded the title compounds [Cp V(mu-F)(2)](4) (1) and [(2,6-i-Pr2C6H3N)(2)MoF2] THF (2). 1 has a tetrameric structure, in which four V atoms can be regarded as being arranged at the vertices of a distorted tetrahedron, with four long edges bridged by one F atom and each of the other two short edges bridged by two F atoms with a mean V-F bond length of 2.00 Angstrom. A hydrolyzed product of 2, [(2,6-i-Pr2C6H3N)(6)Mo-4(mu(3)-F)(2)Me-2(mu-O)(4)] (3) was characterized by elemental analyses and X-ray single crystal study. The X-ray diffraction analysis reveals that 3 has a unique tetranuclear structure, containing two five and two six coordinated Mo atoms connecting each other by four mu-O and two mu(3)-F atoms. The geometries around the two Mo atoms can be described having distorted trigonal bipyramidal and distorted octahedral coordination spheres. respectively. The Mo-(mu-O) bond lengths are 1.813 Angstrom (average) for Eve coordinated Mo atoms and 2.030 Angstrom (average) for those of six coordinated, respectively, indicating an additional pi bonding between five coordinated Mo atoms and the mu-O atoms. The MO-(mu(3)-F) distances range from 2.291 to 2.352 Angstrom
Anthranil: An Aminating Reagent Leading to Bifunctionality for Both C(sp(3))-H and C(sp(2))-H under Rhodium(III) Catalysis
No full textPrevious direct C-H nitrogenation suffered from simple amidation/amination with limited atom-economy and is mostly limited to C(sp(2))-H substrates. In this work, anthranil was designed as a novel bifunctional aminating reagent for both C(sp(2)) H and C(sp(3)) H bonds under rhodium(III) catalysis, thus affording a nucleophilic aniline tethered to an electrophilic carbonyl. A tridendate rhodium(III) complex has been isolated as the resting state of the catalyst, and DFT studies established the intermediacy of a nitrene species
Letter from C. H. Gensler, Havasupai Agency to Carl Hayden
No full textLetter from C. H. Gensler expressing concern on behalf of the Havasupai Tribe regarding the proposed park boundaries
Citations of the author H C Rajpoot
No full textThe list of the articles, research papers, theses, and book chapters globally citing the author H. C. Rajpoot</p
Transition-Metal-Promoted Direct C-H Cyanoalkylation and Cyanoalkoxylation of Internal Alkenes via Radical C-C Bond Cleavage of Cycloketone Oxime Esters
No full textTransition-metal-catalyzed alkyl-Heck-type cross-coupling of olefinic C-H bonds has been a challenge in the C-H activation area. Herein, we report FeCl3-promoted efficient direct C-H cyanoalkylation of internal alkenes, that is, ketene dithioacetals, with cycloketone oxime esters via radical C-C bond cleavage under the redox-neutral conditions. With CuCl2 as the catalyst under a dioxygen atmosphere direct C-H cyanoalkoxylation of the same internal alkenes was achieved. The cyanoalkylated tetrasubstituted alkene products could be diversely transformed to cyanoalkyl-funtionalized N- and S-heterocyclic compounds. The mechanistic studies have revealed that these C-H cyanoalkylation and cyanoalkoxylation reactions proceed through a radical pathway
Letter from Carl Hayden to C. H. Gensler
No full textLetter from Carl Hayden to C. H. Gensler informing him of the proposed Grand Canyon National Park bill
Scanning tunneling spectroscopy on YBa2Cu3Oy/PrBa2Cu3Oy/YBa2Cu3Oy sandwiched junctions and YBa2Cu3Oy/Y0.5Pr0.5Ba2Cu3Oy superlattices
No full textLetter from C. H. Gensler, Havasupai Agency to Carl Hayden
No full textLetter from C. H. Gensler to Carl Hayden asking for a meeting in regards to the Havasupai pasture land in light of the national park bill
Rhodium(III)-Catalyzed C-C Coupling between Arenes and Aziridines by C-H Activation
No full textRhodium(III)-Catalyzed C-C Coupling between Arenes and Aziridines by C-H Activatio
δ-C(sp3)H Activation of Free Alcohols Enabled by Rationally Designed H-Bond-Acceptor Ligands
No full textThe ability to employ a wide range of native substrates is essential for the broad application of transition-metal-catalyzed C–H activation. Recent advances have made native carboxylic acids, ketones, and amines amenable to C(sp3)–H activation, but alcohols, perhaps the most common functionality in organic chemistry, have remained intractable due to their low affinity for late-transition-metal catalysts. Herein we describe the rational development of ligands to overcome this challenge and enable alcohol-directed -C(sp3)–H arylation reactions. Our ligand design strategy employs charge balance and a secondary-coordination-sphere H-bonding interaction—evidenced by SAR studies, computational modelling, and crystallographic data—to stabilize L-type hydroxyl coordination to palladium, thereby facilitating the assembly of the key C–H cleavage transition state. In contrast to prior studies in C–H activation, where secondary interactions were used to control selectivity in the context of established reactivity, this report demonstrates the feasibility of employing secondary interactions to enable challenging novel reactivity by enhancing substrate-catalyst affinity
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