Download PDF
Synthesis 1991; 1991(8): 605-609
DOI: 10.1055/s-1991-26524
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Synthesis of Cyclopropylboronic Acid Esters by Carbene Transfer to 1-Alkenylboronic Acid Esters

Pierre Fontani* , Bertrand Carboni, Michel Vaultier, Gerhard Maas
  • *Groupe de Recherches de Physicochimie Structurale, U.R.A. C.N.R.S. 704, Université de Rennes I, Campus de Beaulieu, F-35042 Rennes Cédex, France and Fachbereich Chemie, Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-6750 Kaiserslautern, Germany
Further Information

Publication History

Publication Date:
29 April 2002 (online)

  PDF Download  Permissions and Reprints All articles of this category

Cyclopropylboronic acid esters 2a-j are prepared conveniently and with high stereoselectivity by cycloaddition of carbenes (or carbenoids) to 1-alkenylboronic acid esters. Methylene transfer is achieved either by the Simmons-Smith reaction or with diazomethane/palladium(II) acetate. The latter procedure is susceptible to steric hindrance, but otherwise, product yields are equally good with both methods. Acyl carbene transfer to vinylboronate 1a succeeds with palladium(II) acetate as catalyst, but not with dirhodium tetraacetate or copper(I) triflate. Oxidative cleavage of the C-B bond of (E)-(2-trimethylsilyl- or (E)-(2-(3-chloropropyl) cyclopropyl)boronate with sodium perborate yields cyclopropanols 5d,h.