An allenic Pauson-Khand-type reaction: a reversal in pi-bond selectivity and the formation of seven-membered rings.
[reaction: see text] Treatment of alkynyl allenes with [Rh(CO)(2)Cl](2) results in a formal [2 + 2 + 1] cycloaddition reaction. This reaction occurs with complete regioselectivity for a variety of substrates affording only 4-alkylidene cyclopentenones in good yields. Moreover, seven-membered rings have been prepared in high yields.
Brummond
Kay M
KM
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. kbrummond@pitt.edu
Chen
Hongfeng
H
Fisher
Kimberly D
KD
Kerekes
Angela D
AD
Rickards
Brenden
B
Sill
Peter C
PC
Geib
Steven J
SJ
D000466:Alkadienes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003500:Cyclization; D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation; D012828:Silicones / Q000737:chemistry
D000466:Alkadienes; D007202:Indicators and Reagents; D012828:Silicones; C025947:propadiene