Synthesis 2019; 51(21): 3947-3963
DOI: 10.1055/s-0037-1611915
short review
© Georg Thieme Verlag Stuttgart · New York

Cyclopropanation Reactions of Semi-stabilized and Non-stabilized Diazo Compounds

Emmanuelle M. D. Allouche
,
This work was supported by the Natural Science and Engineering Research Council of Canada (NSERC) under the CREATE Training Program in Continuous Flow Science and the Discovery Grant Program RGPIN-06438, the Canada Foundation for Innovation Leaders Opportunity Funds 227346, the Canada Research Chair Program CRC-227346, the FRQNT Centre in Green Chemistry and Catalysis (CGCC) Strategic Cluster RS-171310 and Université de Montréal. E. M. D. A. is grateful to Université de Montréal for postgraduate scholarships.
Further Information

Publication History

Received: 26 June 2019

Accepted after revision: 06 August 2019

Publication Date:
23 September 2019 (online)


Abstract

The cyclopropane ring is present in a large number of bio­active molecules as its incorporation often greatly alters their physiochemical properties. The synthesis of such motif is therefore of interest. Diazo compounds are versatile and powerful reagents that can be used in a broad range of reactions, including cyclopropanation processes. However, in case of unstable diazo reagents such as the donor-substituted­ variants, their inherent toxicity and instability have hampered their effective synthesis and utilization. Herein, we report the recent­ advances devoted to the safe and facile production of these potentially hazardous species and their subsequent application in cyclopropanation reactions, allowing the synthesis of more complex cyclopropylated motifs.

1 Introduction

2 Halomethylmetal-Mediated Cyclopropanations

3 Cyclopropanations through Metallic- or Free Carbenes

3.1 Transition-Metal-Catalyzed Decomposition of Diazo Compounds

3.2 Metal-Free Decomposition of Diazo Compounds

4 Michael Induced Ring Closure (MIRC) Reactions

4.1 Sulfur Ylides

4.2 1,3-Dipolar Cycloadditions

5 Conclusion