Synlett 2006(18): 2941-2946  
DOI: 10.1055/s-2006-949625
© Georg Thieme Verlag Stuttgart · New York

Palladium-Catalyzed Heck Alkynylation of Benzyl Chlorides

Catharine H. Larsen, Kevin W. Anderson, Rachel E. Tundel, Stephen L. Buchwald*
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Further Information

Publication History

Received 17 April 2006
Publication Date:
14 August 2006 (online)


An efficient and general protocol for the palladium-catalyzed Heck alkynylation of benzyl chlorides was developed. A ­catalyst system comprised of PdCl2(CH3CN)2 and 2-dicyclohexyl­phosphino-2′,4′,6′-triisopropylbiphenyl (XPhos), with Cs2CO3 as the base, efficiently couples a wide range of functionalized terminal alkynes and substituted benzyl chlorides at 65 °C. We have also demonstrated that the corresponding aryl allene product can be ­selected for using an excess amount of base and higher reaction temperatures (80 °C) in a one-pot procedure.


Reaction of (1-chloroethyl)benzene and 1-decyne resulted in a reproducible yield of 54%; however, the product was unstable and decomposed rapidly.