Relevant factors in the Homo Diazocoupling reaction catalysed by Ruthenium (II) complexes

摘要

Diazocompounds decompose in the presence of Ru(II) complexes giving a Ru-carbenoid intermediate, which can react with more diazocompound yielding olefins [homo diazocoupling (HDC) reaction].1 Thus, ethyl diazoacetate (EDA) catalytically decomposes affording diethyl maleate (DEM) and diethyl fumarate (DEF, the thermodynamic product with E configuration). The DEM/DEF ratio depends on the catalyst, catalyst and EDA concentrations, etc. Most of the reported catalysts have shown the preferential formation of the Z olefin, DEM.Although generic catalytic cycles have been proposed, mechanistic details rationalizing the stereoselectivity of the HDC reactions are unknown nowadays.