Palladium-catalysed borylsilylation and borylstannylative dimerization of 1,2-dienes
作者:Shun-ya Onozawa、Yasuo Hatanaka、Masato Tanaka
DOI:10.1039/a905127i
日期:——
A borylsilane regioselectively adds to 1,2-dienes in the presence of palladium complexes to afford high yields of alkenylboranes having allylsilane moieties, whereas a borylstannane gives a 1 : 2 telomer with 3-methylbuta-1,2-diene due to borylstannylative dimerization.
A highly regio‐ and stereoselective copper‐catalyzed borylcupration of 1,2‐allenylsilanes affords an unexpected regioreversed allylic boronate bearing an extra C−Si bond at the 3‐position, with a thermodynamically disfavored Z geometry. Such stereodefined allylic boronates containing an extra alkenyl silane moiety are very useful organodimetallic reagents for organic synthesis.
NHC–Cu-Catalyzed Protoboration of Monosubstituted Allenes. Ligand-Controlled Site Selectivity, Application to Synthesis and Mechanism
作者:Fanke Meng、Byunghyuck Jung、Fredrik Haeffner、Amir H. Hoveyda
DOI:10.1021/ol4004178
日期:2013.3.15
Two types of NHC-Cu complexes catalyze protoborations of terminal allenes to afford valuable 1,1- or trisubstituted vinylboron species with high site selectivity and stereoselectivity. The scope of the method, application to natural product synthesis, and mechanistic basis for the observed selectivity trends are presented.
<i>β</i>-Borylallylsilanes as a New Tool for Convenient Synthesis of Alkenylboranes
作者:Michinori Suginome、Yutaka Ohmori、Yoshihiko Ito
DOI:10.1021/ja0058381
日期:2001.5.1
Palladium-catalyzed regioselective silaboration of 1,2-dienes
)pinacolborane to allenes in good yields. In the silaboration of terminalallenes having electron-donating substituents such as alkyl and methoxy groups, the SiB bond added to the internal CC bond with regioselective BC and SiC bond formation at the central and substituted carbon atoms of the allene, respectively. In contrast, the silylborane preferably added to the terminal CC bond with exclusive