Mechanism, reactivity, and regioselectivity in rhodiumcatalyzed asymmetric ring-opening reactions of oxabicyclic alkenes: a DFT Investigation
Zheng-Hang Qi, Yi Zhang, Yun Gao, Ye Zhang, Xing-Wang Wang *（王兴旺）and Yong Wang*（王勇）
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China.
Scientific Reports,2017 ,7:40491
The origin of the enantio- and regioselectivity of ring-opening reaction of oxabicyclic alkenes catalyzed by rhodium/Josiphos has been examined using M06-2X density functional theory(DFT). DFT calculations predict a 98% ee for the enantioselectivity and only the 1,2-trans product as one regio- and diastereomer, in excellent agreement with experimental results. The solvent tetrahydrofuran(THF) plays a key role in assisting nucleophilic attack. Orbital composition analysis of the LUMO and the NPA atomic charge calculations were conducted to probe the origins of the regioselectivity. The orbital composition analysis reveals two potential electrophilic sites of the Rh–π-allyl intermediate M3 and the
NPA atomic charges demonstrate that Cα carries more positive charges than Cγ, which suggests that Cα is the electrophilic site.
链接：http://www.nature.com/articles/srep40491