Acylation of oxindoles using methyl/phenyl esters <i>via</i> the mixed Claisen condensation – an access to 3-alkylideneoxindoles
作者:Ramdas Sreedharan、Purushothaman Rajeshwaran、Pradeep Kumar Reddy Panyam、Saurabh Yadav、C. M. Nagaraja、Thirumanavelan Gandhi
DOI:10.1039/d0ob00789g
日期:——
Predominantly, aggressive acid chlorides and stoichiometric coupling reagents are employed in the acylating process for synthesizing carbonyl tethered heterocycles. Herein, we report simple acyl sources, viz. methyl and phenyl esters, which acylate oxindoles via the mixed Claisen condensation. This straightforward protocol is mediated by LiHMDS and KOtBu and successfully applied to a wide range of
Bicarbonyl‐substitutedsulfur ylide is a useful, but inert reagent in organic synthesis. Usually, harsh reaction conditions are required for its transformation. For the first time, it was demonstrated that a new, visible‐light photoredox catalytic annulation of sulfur ylides under extremely mild conditions, permits the synthesis of oxindole derivatives in high selectivities and efficiencies. The key