Copper-Catalyzed Stereospecific Hydroboration of Internal Allylic Alcohols
作者:Enhui Ji、Haiwen Meng、Yue Zheng、Velayudham Ramadoss、Yahui Wang
DOI:10.1002/ejoc.201901435
日期:2019.11.30
Copper‐catalyzed highly stereospecific hydroboration of internal allylic alcohols using a silyl ether transient protection strategy is reported. This in situ protection effectively avoids the preferential side reaction of free hydroxyl group with boron reagent, thus promoting hydroboration. This method provides both the anti‐ and the syn‐ diastereomers of 1,3‐diols in high level of diastereomeric ratios
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.
Stereoselective Synthesis of 1,3-Diol from β-Hydroxyacylsilane via Rearrangement of Phenyl Group from Silicon to Carbon
作者:K Morihata
DOI:10.1016/00404-0399(50)1050r-
日期:1995.7.31
Studies towards 1,3-diol units starting from syn β-hydroxy acylsilanes
Three complementary strategies have been explored to obtain stereodefined 1,3 diols starting from easily accessible syn beta-hydroxy acylsilanes: fluoride induced migrations of substituents on silicon, a Grignard addition followed by protodesilylation and Tischenko-type reactions. Preliminary data on scope and limitations of these processes are presented. (C) 2013 Elsevier Ltd. All rights reserved.