Synthesis 2008(7): 1158-1162  
DOI: 10.1055/s-2007-1000937
PSP
© Georg Thieme Verlag Stuttgart · New York

One-Pot Synthesis and Functionalization of Polyynes via Alkylidene Carbenoids

Thanh Luu, Yasuhiro Morisaki, Rik R. Tykwinski*
Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
Fax: +1(780)4928231; e-Mail: rik.tykwinski@ualberta.ca;
Further Information

Publication History

Received 7 March 2007
Publication Date:
10 January 2008 (online)

Abstract

A one-pot, two-step method for the synthesis of diynes and triynes is reported. The reaction of a dibromoolefinic precursor with BuLi effects a Fritsch-Buttenberg-Wiechell rearrangement and generates a lithium acetylide intermediate, which is then trapped with a variety of electrophiles to produce substituted diynes and triynes. Alternatively, transmetalation from the lithium acetylide to give a zinc acetylide provides a nucleophilic coupling partner for aryl iodides in the presence of palladium to form symmetrical or unsymmetrical diynes and triynes via the Negishi coupling.

1

Current address: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Japan.

12

Toluene was used instead of hexanes to achieve a higher temperature for reflux in the Negishi cross-coupling.