86604-06-0Relevant academic research and scientific papers
PREFERENTIAL FORMATION OF THE Z ISOMERS OF CINNAMALDEHYDES IN THE REARRANGEMENT OF ARYLETHYNYLCARBINOLS CATALYZED BY POLYVANADIOORGANOSILOXANES
Gulyi, S. E.,Erman, M. B.,Novikov, N. A.,Aul'chenko, I. S.,Vol'pin, M. E.
, p. 715 - 721 (2007/10/02)
During the rearrangement of secondary and tertiary aryl(ethynyl)carbinols, catalyzed by polyvanadioorganosiloxanes, the thermodynamically less favorable Z isomers of the cinnamaldehydes are formed preferentially.It was shown that zero order in the initial carbinol and pseudofirst order in the catalyst are observed in the rearrangement.The activation parameters of the reaction, which confirm that the rearrangement takes place through a highly polar cyclic transition state, were determined.The dependence of the reaction rate on the structure of the initial carbinol is discussed.The Z-stereoselectivity of the rearrangement is explained by the presence of steric effects, which show up at the stage of the conversion of the intermediate allenyl vanadate into cinnamaldehyde.
