Organoboranes for synthesis. 7. An improved general synthesis of primary amines from alkenes via hydroboration-organoborane chemistry
作者:Herbert C Brown、Kee-Won Kim、Morris Srebnik、Singaram Bakthan
DOI:10.1016/s0040-4020(01)83445-1
日期:——
Triorganylboranes, R3B, and diorganylborinic esters, R2BOR', react readily with preformed chloramine or hydroxylamine-0-sulfonic acid to produce the corresponding primary amines, RNH2. However, the product of the reaction following hydrolysis is the boronic acid, RB(OH)2, limiting the yield to 67% for R3B and to 50% for R2BOR'. This problem has now been overcome with the help of lithium dimethylborohydride
Triorganylboranes,R 3 B,和diorganylborinic酯,R 2 BOR”,具有预制氯胺或羟胺容易反应0磺酸,以产生相应的伯胺,RNH 2。但是,水解后反应的产物是硼酸RB(OH)2,R 3 B的产率限制为67 %,R 2 BOR'的产率限制为50%。现在已经借助二甲基硼氢化锂克服了这个问题,该二甲基硼氢化锂易于原位转化为二甲基硼烷。代表性烯烃通过二甲基硼烷进行氢硼化提供相应的单有机基二甲基硼烷RMe 2B.用羟胺-O-磺酸处理该中间体提供所需的胺RNH 2,分离产率为73%至95%。反应在完全保留的情况下进行,从而再现了有机硼烷RMe 2 B中有机基团的精确结构。