Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine
作者:Nilesh S. Khonde、Madhukar S. Said、Jagjivan K. Sabane、Jayant M. Gajbhiye、Pradeep Kumar
DOI:10.1016/j.tet.2021.132510
日期:2021.11
An inexpensive and commercially available Tf2NH-catalyzed 1,6-conjugate addition of imidazopyridine (IMPY) heterocycles to para-quinone methides (p-QMs) is reported. The present transformation provides a diverse class of C3-functionalized triarylmethanes heterocyclic derivatives of imidazopyridine. These metal-free transformations provided a very broad substrate scope of conjugate addition product
A New Organocatalytic Concept for Asymmetric α-Alkylation of Aldehydes
作者:Lorenzo Caruana、Florian Kniep、Tore Kiilerich Johansen、Pernille H. Poulsen、Karl Anker Jørgensen
DOI:10.1021/ja510475n
日期:2014.11.12
The organocatalyticasymmetric α-alkylation of aldehydes by 1,6-conjugated addition of enamines to p-quinone methides is described. Employing a newly developed class of chiral secondary amine catalysts, α-diarylmethine-substituted aldehydes with two contiguous stereocenters have been synthesized in a simple manner with good diastereocontrol and excellent enantioselectivity.
Asymmetric Organocatalytic 1,6-Conjugate Addition of <i>para-</i>Quinone Methides Using [1,2]-Phospha-Brook Rearrangement
作者:Qingfa Tan、Ning Guo、Linhan Yang、Fei Wang、Xiaoming Feng、Xiaohua Liu
DOI:10.1021/acs.joc.3c00910
日期:2023.7.7
efficient tool for generation of anionic nucleophiles is an attractive strategy for the construction of C–C bonds in organic synthesis. Herein, we report organocatalytic 1,6-conjugate addition of para-quinone methides utilizing Pudovik addition/[1,2]-phospha-Brook rearrangement. Chiral guanidine–sulfonamide catalyzed the three-component reaction efficiently, providing biologically active oxindole/biaryl/phosphorus-based