Synlett 2005(4): 670-672  
DOI: 10.1055/s-2005-862375
LETTER
© Georg Thieme Verlag Stuttgart · New York

Dramatic Effect of Boron-Based Lewis Acids in Cross-Metathesis Reactions

Emeline Vedrenne, Hervé Dupont, Sabrina Oualef, Laurent Elkaïm*, Laurence Grimaud*
Laboratoire Chimie et procédés, Ecole Nationale Supérieure de Techniques Avancées, 32 Bd Victor, 75739 Paris Cedex 15, France
Fax: +33(1)45525587; e-Mail: laurence.grimaud@ensta.fr ;
Further Information

Publication History

Received 18 November 2004
Publication Date:
22 February 2005 (online)

Abstract

Amino compounds such as allylic carbamates or amides are poor partners in cross-metathesis reactions because of possible coordination of the emerging carbene to the polar functional group. Whereas the use of titanium Lewis acid catalysts was unsatisfactory, an impressive increase in yields was obtained with boron-based Lewis acids.

    References

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8

Usually CM coupling requires two or three equivalents of one partner. Although use of more than one equivalent of one of the olefin partner slightly improves the yield of the coupling.