Further studies on the application of vinylogous amides and β-halovinylaldehydes to the regiospecific synthesis of unsymmetrical, polyfunctionalized 2,3,4- and 1,2,3,4- substituted pyrroles
John T. Gupton, Alex Shimozono, Evan Crawford, Joe Ortolani, Evan Clark, Matt Mahoney, Campbell Heese, Jeffrey Noble, Carlos Perez Mandry, Rene Kanters, Raymond N. Dominey, Emma W. Goldman, James A. Sikorski, Daniel C. Fisher
Index: 10.1016/j.tet.2018.04.017
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Abstract
Highly functionalized pyrroles with appropriate regiochemical functionality represent an important class of marine natural products and potential drug candidates. We describe herein a detailed study of the reaction of α-aminoacid esters with vinylogous amides and also β-halovinylaldehydes for the regiospecific synthesis of 2,3,4-trisubstituted and 1,2,3,4-tetrasubstituted pyrroles. Since the vinylogous amides and β-halovinylaldehydes are readily available precursors, rapid access to a wide variety of unsymmetrically substituted pyrroles is accomplished via this methodology.