Asymmetric Catalytic Enantio- and Diastereoselective Boron Conjugate Addition Reactions of α-Functionalized α,β-Unsaturated Carbonyl Substrates
作者:Jian-Bo Xie、Siqi Lin、Shuo Qiao、Guigen Li
DOI:10.1021/acs.orglett.6b01998
日期:2016.8.5
established for the asymmetric boron conjugate addition of B2pin2 onto α-functionalized (involving C, N, O, and Cl) α,β-unsaturated carbonyls under mild, neutral conditions involving Cu[(S)-(R)-ppfa]Cl, AgNTf2, and alcohols. The dual additives of AgNTf2 and alcohols were found to play crucial roles for achieving high catalytic activity and enantio- and diastereoselectivity (up to 98% ee and 70:1 dr).
作者:Daniela Acetti、Elisabetta Brenna、Claudio Fuganti、Francesco G. Gatti、Stefano Serra
DOI:10.1002/ejoc.200901006
日期:2010.1
Reduction of β-hydroxy ketones to the corresponding 1,3-diols by baker'syeast was investigated, in order to develop methods for simultaneous control over the configurations of multiple stereogenic centres. The reactions were found to be enantiospecific and generally characterised by good diastereoselectivity. Substrates with a substituent at the carbon atom in the α position were also considered.
Stereo- and Regioselectivity of Reactions of Siliranes with Aldehydes and Related Substrates
作者:Paul M. Bodnar、Wylie S. Palmer、Brian H. Ridgway、Jared T. Shaw、Jacqueline H. Smitrovich、K. A. Woerpel
DOI:10.1021/jo970263k
日期:1997.7.1
Siliranes undergo stereoselective and regioselective insertions of benzaldehyde to provide oxasi-lacyclopentane products. The thermal reaction (>100 degrees C) leads to more decomposition and side products, whereas the catalyzed variant (t-BuOK, (25 degrees C) proceeds more cleanly with a high degree of inversion (>95%). Treatment of siliranes with enolizable aldehydes leads to silyl enol ethers. The reaction of a silirane at high temperatures with an imine leads to reductive dimerization, presumably by way of intermediate-free silylene. The mechanism for the catalyzed insertion of benzaldehyde is discussed.
Prins-Reaktionen mit Arylaldehyden, 5. Mitt.: Zur Umsetzung mit 2-Buten und mit Cyclohexen
作者:Herfried Griengl、Arnulf Mayer、Klaus Peter Geppert
DOI:10.1007/bf00905070
日期:——
Construction of Homoallylic Alcohols from Terminal Alkynes and Aldehydes with Installation of <i>syn</i>-Stereochemistry
作者:Tomoya Miura、Yui Nishida、Masahiro Murakami
DOI:10.1021/ja502169d
日期:2014.4.30
A cationic rhodium(I) catalyst turns 2-silyl-1-alkenylboronate, readily prepared from a terminal alkyne, into the corresponding allylboronate species, which immediately undergoes nucleophilic addition to an aldehyde to give a syn-homoallylic alcohol stereoselectively.