The Efficiency of the Metal Catalysts in the Nucleophilic Substitution of Alcohols is Dependent on the Nucleophile and Not on the Electrophile
作者:Srijit Biswas、Joseph S. M. Samec
DOI:10.1002/asia.201201178
日期:2013.5
efficiency and selectivity to perform the desired substitution. Interestingly, the selectivity of the alcohols to produce the desired substitution products was found to be independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation. Catalysts based on iron(III), bismuth(III), and gold(III) show higher conversions for S‐, C‐, and N‐centered
Catalyst development for organocatalytic hydrosilylation of aromatic ketones and ketimines
作者:Andrei V. Malkov、Angus J. P. Stewart-Liddon、Grant D. McGeoch、Pedro Ramírez-López、Pavel Kočovský
DOI:10.1039/c2ob25472g
日期:——
A new family of Lewis basic 2-pyridyl oxazolines have been developed, which can act as efficientorganocatalysts for the enantioselective reduction of prochiral aromatic ketones and ketimines with trichlorosilane, a readilyavailable and inexpensive reagent. 1-Isoquinolyl oxazoline, derived from mandelic acid, was identified as the most efficient catalyst of the series, capable of delivering high
Spatial effects of oxovanadium-immobilized mesoporous silica on racemization of alcohols and application in lipase-catalyzed dynamic kinetic resolution
We recently reported a new dynamic kineticresolution (DKR) method based on the combination of lipase-catalyzedkineticresolution of racemic alcohols and the V-MPS3-catalyzed in situ racemization of less reactive alcohol enantiomers. In V-MPS3, oxovanadium moieties were covalently bound to the inner surface of mesoporous silica (MPS) with a pore size of about 3 nm. The catalytic activity of V-MPS3
Boronic Acid Catalysis as a Mild and Versatile Strategy for Direct Carbo- and Heterocyclizations of Free Allylic Alcohols
作者:Hongchao Zheng、Sina Ghanbari、Shinji Nakamura、Dennis G. Hall
DOI:10.1002/anie.201201620
日期:2012.6.18
BAC to the future: Boronic acid catalysis (BAC) was applied to the direct activation of alcohols leading to the preparation of carbocycles (see scheme), benzofurans, tetrahydrofurans, pyrrolidines, pyrans, piperidines, and various polycyclic compounds. The reactions proceed under mild conditions that circumvent the use of reactive leaving groups like halides.
catalytic azidation of primary, secondary, and tertiary allylic alcohols has been developed. This new azidation reaction affords the corresponding allylic azides in high to excellent yields and regioselectivities. The reaction provides straightforward access to allylic azides that are valuable intermediates in organic synthesis, including the preparation of primary amines or 1,2,3-triazole derivatives