Transition-Metal-Free and Selective Deconstructive Carbonyl Olefination of α-Hydroxy Ketones: A Complementary Approach to Knoevenagel Reaction
作者:Anil Kumar、Sandeep Sandeep、Vaneet Saini、Chayawan Chayawan、Ganga R. Chaudhary、Paloth Venugopalan
DOI:10.1055/a-2114-7802
日期:2023.10
While the carbonylolefination has been extensively studied and well documented, use of α-hydroxy ketones as precursors for the carbonylolefination is not reported, till date. Herein, a transition-metal-free and selective Knoevenagel-type deconstructive carbonylolefination of α-hydroxy ketones using arylacetonitriles under mild reaction conditions is presented. The reaction affords valuable scaffolds
A very simple, yet efficient synthetic methodology, to obtain 3,4-diaryl-substituted pyrroles is described. The approach is based on the Knoevenagel condensation between arylacetonitriles and substituted aromatic aldehydes, followed by conjugate addition of cyanide to afford succinonitriles in excellent yields. The products thus obtained were subjected to DIBAL-H reduction, followed by cyclization under acidic conditions to produce the corresponding pyrroles in good overall yields. The utility of this protocol is exemplified by the synthesis of the marine alkaloids lamellarins O and Q.