An unprecedented N- to C-sulfonyl migration in the reaction of azomethine amine and allenoates: access to arylsulfonylmethyl substituted pyrazolo[1,5-c]quinazoline and mechanistic studies

Arshad J Ansari; Aabid Abdullah Wani; Antim K Maurya; Sarika Verma; Vijai K Agnihotri; Ashoke Sharon; Prasad V Bharatam; Devesh M Sawant

doi:10.1039/c9cc06751e

An unprecedented N- to C-sulfonyl migration in the reaction of azomethine amine and allenoates: access to arylsulfonylmethyl substituted pyrazolo[1,5-c]quinazoline and mechanistic studies

Chem Commun (Camb). 2019 Dec 5;55(98):14825-14828. doi: 10.1039/c9cc06751e.

Authors

Arshad J Ansari¹, Aabid Abdullah Wani, Antim K Maurya, Sarika Verma, Vijai K Agnihotri, Ashoke Sharon, Prasad V Bharatam, Devesh M Sawant

Affiliation

¹ School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer-305817 (Raj), India. dms@curaj.ac.in.

PMID: 31763629
DOI: 10.1039/c9cc06751e

Abstract

A serendipitous discovery of [1,3]-sulfonyl migration has been made in the two-component reaction of azomethine imine and allenoates. Current methodology involving N-S bond cleavage and C-S bond formation provided easy access to biologically important arylsulfonylmethyl substituted pyrazolo[1,5-c]quinazolines. Subsequently, a one-pot sequential protocol has been developed from the easily available starting material. The mechanistic investigation using quantum chemical methods revealed that the sulfonyl migration step is a concerted [1,3]-sigmatropic shift.