First Intermolecular Cyclopropanation of Fischer Dialkylaminocarbene Complexes. Synthesis of 1-Aminocyclopropanecarboxylic Acid Derivatives

Abstract

[reaction: see text] The first cyclopropanation reaction of olefins with Fischer dialkylaminocarbene complexes is presented. The reaction yields 1-aminocyclopropanecarboxylic acid derivatives in a single step, usually with high diastereoselectivity. An approach to the asymmetric version of this reaction is also presented. The synthetic utility of the procedure is exemplified by the synthesis of both cycles of metanoproline in a single step. In addition, the synthesis of the first Fischer carbene containing a halocarbonyl group is reported.

Table of Contents

“…Unfortunately, save for a beautiful example by Barluenga et al. involving a chromium‐based dialkylamino carbenoid,11 Fischer carbenoids cannot be used in such reactions since they undergo competing metathesis. Herein, we report a simple and direct one pot synthesis of protected aminocyclopropanes, a reaction which features the first in situ generation of hitherto unknown carbamatoorganozinc carbenoids (Scheme ).…”

The chemistry of the carbon–transition metal double and triple bond: annual survey covering the year 2002

“…Successful cyclopropanation of styrene using aminocarbene complexes that feature an acyl group at the carbene carbon (e.g. 270, Scheme 22) was reported [470]. Cyclopropanation was observed when chromium carbene acylates were treated with ␤,␥-unsaturated acid chlorides [471].…”

Asymmetric Synthesis of Aminocyclopropanes and N‐Cyclopropylamino Alcohols Through Direct Amidocyclopropanation of Alkenes Using Chiral Organozinc Carbenoids

“…To the best of our knowledge, the addition of a chromium-based Fischer carbenoid possessing a glycine unit by Barluenga provided the first example of this strategy. [9] Within our own group, we have demonstrated that organozinc carbenoids can be simply generated from carbonyl compounds [10] or their acetal or ketal derivatives, [11] with-cyclopropane product is favoured, although certain cyclic alkenes such as indene favour the formation of the endo cyclopropane. The products can be readily elaborated to produce cyclopropylamino alcohols and amino acids.…”