Highly regioselective hydroboration of unsymmetrical internal alkynes remains a significant challenge for synthesizing valuable alkenylboronate esters. Herein, we describe an easily synthesizable pincer NHC-based Co complex as a catalyst for the cis-α selective hydroboration of unactivated internal alkynes and the cis-β selective hydroboration of activated internal alkynes with pinacolborane. The reaction
不对称内炔烃的高区域选择性硼氢化仍然是合成有价值的烯基硼酸酯的重大挑战。在此,我们描述了一种易于合成的钳形 NHC 基 Co 配合物,作为未活化内炔烃的顺α选择性硼氢化和活化的内炔烃与频立硼烷的顺β选择性硼氢化的催化剂。该反应表现出高化学选择性、区域选择性和立体选择性,并且在无碱反应条件下催化剂表现出高效率和极低负载量。反应范围由具有多种官能团的炔烃证明。机理研究表明,一种可行的钴硼基中间体可以解释不寻常的区域选择性。
Aitken, R. Alan; Atherton, J. Ian, Journal of the Chemical Society. Perkin transactions I, 1994, # 10, p. 1281 - 1284
作者:Aitken, R. Alan、Atherton, J. Ian
DOI:——
日期:——
Synthesis of acetylenes from carboxylic acid derivatives via .beta.-keto sulfones
作者:Paul A. Bartlett、Frederick R. Green、Esther H. Rose
DOI:10.1021/ja00483a035
日期:1978.7
AITKEN, R. A.;ATHERTON, J. I., J. CHEM. SOC. CHEM. COMMUN., 1985, N 16, 1140-1141