Gold-Catalyzed Dearomative Spirocyclization of <i>N</i>-Aryl Alkynamides for the Synthesis of Spirolactams
作者:Taylor L. Vacala、Paul R. Carlson、Asa Arreola-Hester、Chloé G. Williams、Evana W. Makhoul、Paul A. Vadola
DOI:10.1021/acs.joc.7b03125
日期:2018.2.2
A catalytic redox-neutral method for the synthesis of spirolactams proceeding through the dearomative spirocyclization of N-aryl alkynamides is reported. In contrast to stoichiometric activating agents employed for related transformations, we show that the use of 5 mol % of Au(PPh3)Cl and AgOTf in dichloroethane at 50–80 °C leads to selective spirocyclization, furnishing the products in yields of 35–87%
The catalyticenantioselective propargylation of aldehydes with newly prepared stannyl allenyl amides is described. The reaction has been accomplished by usingcatalytic amounts of indium chloride, zinc chloride, and a chiral BINOL derivative, affording amide-functionalized homopropargyl alcohols in excellent yields and enantioselectivities.