Copper‐Catalyzed Asymmetric 1,4‐Hydroboration of Coumarins with Pinacolborane: Asymmetric Synthesis of Dihydrocoumarins
作者:Hyohyun Kim、Jaesook Yun
DOI:10.1002/adsc.201000310
日期:2010.10.9
An efficient asymmetric addition of pinacolborane to 4-substituted coumarins proceeded with high enantioselectivity in the presence of a copper(I)-QuinoxP complex as a catalyst to produce the corresponding 1,4-hydroboration products. Treatment of the intermediates with electrophiles, without isolation, resulted in enantioenriched dihydrocoumarins. The utility of this protocol was demonstrated in the
A highly efficient enantioselective [1,3] O-to-C rearrangement of racemic vinyl ethers that operates under mild conditions was developed. This method with chiral ferrous complex catalyst provided an efficient access to a wide range of chromanols with high yields and excellent enantioselectivities. In addition, an important urological drug (R)-tolterodine and others were easily obtained after simple