Remarkable Stereocontrol in the Palladium-Catalysed Cyclopropanation of Vinyl- and Dienylboronates by Substituted Diazoalkanes
作者:István E Markó、Takuya Kumamoto、Thierry Giard
DOI:10.1002/1615-4169(200212)344:10<1063::aid-adsc1063>3.0.co;2-l
日期:2002.12
Substituted diazoalkanes react smoothly, in the presence of catalytic amounts of Pd(OAc)(2), with a range of vinyl- and dienylboronates, affording in good to excellent yields, the corresponding trisubstituted cyclopropanes. The reaction is remarkably regio-, chemo-, and diastereoselective. The synthetic utility of this novel protocol is illustrated by the efficient assembly of the middle fragment of ambruticin.