Selective arylation and vinylation at the α position of vinylarenes.
In intermolecular Heck reactions of styrene and vinylarenes, the aryl and vinyl groups routinely insert at the β position. However, selective insertion at the α position has been very rare. Herein, we provide a missing piece in the palette of Heck reaction, which gave >20:1 α selectivity. The key to our success is a new ferrocene 1,1'-bisphosphane (dnpf) that carries 1-naphthyl groups. Our mechanistic studies revealed that the high α selectivity is partly attributable to the steric effect of dnpf. The rigid and bulky 1-naphthyl groups of dnpf sterically disfavor β insertion.
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
Yinjun
Y
Zou
Liena
L
Qin
Xinfeng
X
Ren
Yunpeng
Y
Lu
Yongxin
Y
Li
Jianrong Steve
JS
Zhou