Title

Metal Salt Catalyzed Carbenoid-XIII. On The Mechanisms Of Cyclopropanation And Allylic CH Insertions By Diazo Esters In The Presence Of Olefins And Homogeneous Copper Catalysts

Abstract

Evidence is presented demonstrating the existence of two paths to the title processes which arise from a common intermediate. A rationale involving catalyzed addition of the diazo compound to the olefin and carbenoid addition to the olefin is proposed. The penultimate intermediate has one new CC bond formed. It is partitioned between products by forming the second CC bond or formation of a hydrocarbenoid allyl complex which collapses to the allylic CH insertion products. Cyclopropanation occurs stereospecifically. The proposed mechanism accounts for the stereospecificity of cyclopropanation, the variance of syn/anti ratios with catalyst concentration when diazoacetic ester is employed and optical inductions with chiral catalysts. The question of whether the alleged carbenoid and/or the penultimate intermediate contain N2 is not answered although it is felt that a cupro-cyclobutane intermediate is the most probable intermediate before product partitioning. © 1976.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

0040-4020

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

01 Jan 1976

 
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