PAPER	Synthesis 2004: 2186-2190   DOI: 10.1055/s-2004-829178
© Georg Thieme Verlag Stuttgart · New York
An Improved Catalytic System, Pd(PPh3)4/PhCOOH Combined Catalyst, for the Allylation of Carbon Pronucleophiles with Allenes
Nitin T. Patil, Nirmal K. Pahadi, Yoshinori Yamamoto*
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan e-Mail: yoshi@yamamoto1.chem.tohoku.ac.jp;
Received 21 April 2004

Abstract

The reaction of allenes with active methynes and methylenes proceeded smoothly in the presence of Pd(PPh₃)₄/PhCOOH combined catalyst to give the corresponding monoallylated products with E-stereoselectivity in good to high yields. This result is in marked contrast to the previous finding that the reaction of allenes with active methynes, in the presence of Pd₂(dba)₃·CHCl₃/dppb catalyst, affords the allylation products in lower yield with lower stereoselectivities.

Key words

palladium - carboxylic acids - catalysis - allenes - C-nucleophiles