Publication date: 3 January 2019
Source: Tetrahedron Letters, Volume 60, Issue 1
Author(s): Khyati Shukla, Sadhna Shah, Nirmal K. Rana, Vinod K. Singh
An economical approach for the diastereoselective synthesis of highly functionalized carbocyclic spiropyrazolone derivatives having one quaternary and two tertiary stereocenters along with one exocyclic double bond exploiting dual organo-silver sequential catalysis has been developed. The unified method to both cyclohexyl and cyclopentyl spirocompounds involves the reaction of γ- and β-nitroalkynes with alkylidene pyrazolones catalyzed by Hünig’s base followed by carbophilic activation of the triple bond with a Ag(I) salt leading to cyclization via hydroalkylation.