Microwave effect on catalytic enantioselective Claisen rearrangement
作者:Kazuya Nushiro、Satoshi Kikuchi、Tohru Yamada
DOI:10.1039/c3cc44610g
日期:——
Catalytic enantioselective Claisen rearrangement was drastically enhanced under microwave irradiation conditions without any loss of the enantioselectivity. Based on Arrhenius plots it was revealed that enantioselectivity decreased as the internal reaction temperature increased. Therefore, this reaction acceleration would NOT be caused by only a simple thermal effect.
Catalytic Asymmetric Claisen Rearrangement of Enolphosphonates: Construction of Vicinal Tertiary and All-Carbon Quaternary Centers
作者:Jiajing Tan、Cheol-Hong Cheon、Hisashi Yamamoto
DOI:10.1002/anie.201203092
日期:2012.8.13
A copper‐catalyzed enantioselective Claisenrearrangement of easily accessible enolphosphonates using the commercially available PhBOX as the chiral ligand was developed. A wide range of rearrangement products with contiguous tertiary and all‐carbon quaternarycenters were obtained in excellent yields and stereoselectivities. The α‐ketophosphonate substituent in the products could be easily transformed