Geminal dimetalation of alkylidene-type carbenoids with silylboranes and diborons
摘要:
A novel and efficient method for gem-dimetalation of carbenoids has been demonstrated. Treatment of alkylidene-type lithium carbenoids with such an interelement compound as silylborane or diboron to generate the corresponding borate complex, followed by warming to room temperature, induced migration of the silyl or boryl group from a negatively charged boron atom to the carbenoid carbon to afford 1-boryl-1-silyl-1-alkenes or 1,1-diboryl-1-alkenes in good yields. Carbon-carbon bond forming transformations of the gem-dimetalated compounds mediated by boron or silicon is also described. (C) 2002 Elsevier Science Ltd. All rights reserved.
Treatment of 1,1-[bis(pinacolato)boryl]alkenes with excess of 1-bromo-1-lithioethene was found to give 2,3-bis[(pinacolato)boryl]-1,3-dienes in moderate to good yields. Synthetic applications of 2,3-[bis(pinacolato)boryl]-1,3-butadiene were also demonstrated.
Palladium/Charcoal-Catalysed Olefin Reduction for the Simple and Efficient Synthesis of Substituted gem-Diborylalkanes
作者:Santanu Panda、Kanak Kanti Das、Debraj Ghorai、Somenath Mahato
DOI:10.1055/a-2147-1336
日期:2023.11
bifunctional reagents that can be applied for the synthesis of simple to complex skeletons. Herein, we report a Pd-catalysed hydrogenation method for the synthesis of gem-diborylalkanes from the corresponding gem-diborylalkenes, which are themselves prepared from the corresponding aldehydes and ketones using known procedures. In addition, transformations of two representative gem-diborylalkane products