Regioselective and Stereospecific Copper-Catalyzed Deoxygenation of Epoxides to Alkenes.
Two copper salts (Cu(CF3CO2)2 and IMesCuCl) were identified as earth-abundant, inexpensive, but effective metal catalysts together with diazo malonate for chemo-/regioselective and stereospecific deoxygenation of various epoxides with tolerance of common functional groups (alkene, ketone, ester, p-methoxybenzyl, benzyl, tert-butyldimethylsilyl, and triisopropylsilyl). In particular, the unprecedented regioselectivity allowed for the first time monodeoxygenation of diepoxides to alkenyl epoxides. Density functional theory mechanistic studies showed that the deoxygenation occurred by collapsing the free ylide, unfavoring the possible intuitive pathway via cycloreversion of possible oxetane.
Department of Chemistry, The Hong Kong University of Science and Technology , Clearwater Bay, Kowloon, Hong Kong, China.
Jingxun
J
Yu
Department of Chemistry, The Hong Kong University of Science and Technology , Clearwater Bay, Kowloon, Hong Kong, China.
Yu
Y
Zhou
Department of Chemistry, The Hong Kong University of Science and Technology , Clearwater Bay, Kowloon, Hong Kong, China.
Zhenyang
Z
Lin
Department of Chemistry, The Hong Kong University of Science and Technology , Clearwater Bay, Kowloon, Hong Kong, China.
Rongbiao
R
Tong