For the first time, Ti(O-iPr)4-EtMgBr carbozincation of dialkyl-substituted alkynes with Et2Zn was carried out. It was found that the reaction of 1,2-disubstituted alkynes (5-decyne, 4-octyne, 3-hexyne) with Et2Zn is accompanied by the regioselective formation of stereoisomeric tetraalkyl-substituted hexa-1,3-diene derivatives in high yield. It was found that 2-zincoethylzincation of dialkyl-substituted alkynes in the presence of catalytic amounts of Ti(O-iPr)4 and EtMgBr does not stop at the stage of ethylzincation of the triple bond, but is accompanied by the involvement of a second alkyne molecule with the formation of two stereoisomeric hexa-1,3-diene derivatives. The effect of the nature of the solvent on the carbozincation of dilkyl-substituted acetylenes under the conditions of titanium-magnesium catalysis was studied.
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Ti(O-iPr)4-EtMgBr-catalyzed reaction of dialkyl-substituted alkynes with Et2Zn
Published:
12 November 2021
by MDPI
in The 25th International Electronic Conference on Synthetic Organic Chemistry
session General Organic Synthesis
Abstract:
Keywords: Alkynes, diethylzinc, tetraisopropoxytitanium, ethylmagnesium bromide, carbozincation