咪唑基团与硼烷的缩合导致分子单元带有N B R 2 -N桥是通过将三个咪唑单元连接到一个磷原子上来完成的。这样,硼桥联的三咪唑基膦3 – 7的合成产率很高。手性衍生物5a,5d,6和7是C 3对称的,而5b和5c没有携带对称元素(C 1)。通过在三个桥连的硼原子上引入不同的取代基,可以轻松地调节配体的空间体积。所有的膦都具有在91–93°之间的小CPC角,从而导致磷原子处的as型孤对供体,并具有合理的π接受特性。的Ni(8)和Au金属复合物(9,10)具有非常短的金属磷键合成。金属-磷之间的距离短是磷化氢孤对显着的s-字符的结果。
Organoboranes. 56. Systematic study of the reactions of 1-alkenylboronic esters with representative organolithium and Grignard reagents to provide an efficient, selective synthesis of organyl-1-alkenylborinic esters
作者:Herbert C. Brown、Nagarajan Vasumathi、Navalkishore N. Joshi
DOI:10.1021/om00028a021
日期:1993.4
A selective reaction of the ''ate'' complexes formed with 1-alkenylboronic esters and organolithium or Grignard reagents, by treatment with either Bronsted or Lewis acids at -78-degrees-C to give the corresponding organylalkenylborinic esters, is explored in this study. This systematic, detailed study reveals that the nature of the alkoxy group on boron, the nature and the amount of the alkyllithium or Grignard reagent used, the solvent, the reaction temperature, and the nature and amount of the acid used all play significant roles in influencing both the yield and the selectivity achieved for the formation of the desired organylalkenylborinates. Optimized procedures for the syntheses of representative organylalkenylborinic esters in high yield are summarized.
Organoboranes. 31. A simple preparation of boronic esters from organolithium reagents and selected trialkoxyboranes
作者:Herbert C. Brown、Thomas E. Cole
DOI:10.1021/om50004a009
日期:1983.10
Brown, Herbert C.; Srebnik, Morris; Cole, Thomas E., Organometallics, 1986, vol. 5, # 11, p. 2300 - 2303
作者:Brown, Herbert C.、Srebnik, Morris、Cole, Thomas E.