organolithiums, Grignardreagents, or zincates to sulfinylnitriles triggers a facile sulfinyl–metal exchange to afford N‐ or C‐metalated nitriles. Sulfinyl–magnesium exchange–alkylations efficiently install quaternary and tertiary centers, even in the case of tertiary sulfinylnitriles that contain a highly acidic methine proton. α‐Sulfinylalkenenitriles afford moderately nucleophilic magnesiated nitriles, and
An α-Diaminoboryl Carbanion Assisted Stereoselective Single-Pot Preparation of α,β<i>-</i>Disubstituted Acrylonitriles
作者:Takashi Tomioka、Rambabu Sankranti、Trey G. Vaughan、Toshihide Maejima、Takayoshi Yanase
DOI:10.1021/jo201280x
日期:2011.10.7
An alpha-diaminoboryl carbanion-mediated one-pot olefination directly converts an acetonitrile or the homologous nitrile into a series of alpha,beta-disubstituted acrylonitriles in a stereoselective manner. The protocol involves the formation of an alpha-substituted alpha-diaminoboryl acetonitrile and subsequent olefination with an aldehyde. The use of an aryl or conjugated aldehyde preferentially leads to a (Z)-acrylonitrile, while an aliphatic aldehyde gave an (E)-isomer as a major product. Two complementary approaches, a linear method and a divergent method, are developed.
Continuous Flow Magnesiation or Zincation of Acrylonitriles, Acrylates, and Nitroolefins. Application to the Synthesis of Butenolides
作者:Maximilian A. Ganiek、Matthias R. Becker、Marthe Ketels、Paul Knochel
DOI:10.1021/acs.orglett.6b00086
日期:2016.2.19
Scalable continuousflow procedures are reported for the metalation and downstream functionalization of β-substituted acrylates. The flow conditions allow the metalation of acrylonitriles, acrylates, and nitroolefins at 0.25–2.50 mmol/min conversion rates. Magnesiations can be performed with short residence times (1–20 min) and near-ambient temperature using TMPMgCl·LiCl. Further, high temperature