2‐Oxo‐Driven Coupling Reactions of 2‐Oxo Aldehydes/2‐Oxo Iminium Ions and Hydroperoxides at Room Temperature

Abstract

An efficient 2‐oxo‐group‐promoted direct coupling reaction between 2‐oxo aldehydes and hydroperoxides has been developed. The method has been used successfully for the generation of different 2‐oxo esters and acids. This reaction harnesses the hydrogen‐bonding‐induced self‐decomposition tendency of hydroperoxides; the intermediates produced by this process then attack the aldehyde or iminium ion to generate cross‐coupled products either by direct coupling or by an amine‐catalysed pathway. No external oxidants or metal catalysts are required for our method, and the reaction takes place at room temperature.

Exocyclic N-Acyliminium Ion (NAI) Cyclization: Access to Fully Substituted Oxazoles and Furocoumarins

“…All the phenylglyoxals were synthesized according to the literature procedures . To a 50 mL two-neck round-bottom flask were added SeO 2 (4.99 g, 45.0 mmol), H 2 O (0.76g, 42.5 mmol) and 1,4-dioxane (25.0 mL) and fixed a condenser.…”

A Facile Approach to α‐Keto Esters via Oxidative Esterification of α‐Amino Carbonyl Compounds

“…Additionally, they have been widely used as precursors for many useful functional groups . In view of their vast potential, the approaches to α ‐keto esters have received significant attention in recent years . In 2007, Murakami and co‐workers developed a rhodium‐catalysed reaction of cyanoformate with arylboronic acids (Scheme a) .…”

Access to Functionalized Thiazolothiadiazoles via the Chemoselective Cascade Heteroannulation of Thioamides with Hypervalent Iodine Reagents

“…The intermediate A undergwent intramolecular cyclization, followed by the elimination of amine, to produce intermediate B in the form of thiadiazolium salt, which was further chemoselectively attacked by the S -nucleophile of β-ketothioamide to deliver intermediate C . The aroyl group play a crucial role in the conversion of intermediate C to C′ and promotes the reaction by enabling the easy elimination of the aniline moiety, affording the formation of desired thiazolothiadiazole 3 . In order to support our mechanism, we performed the HRMS analysis of the reaction between 1a and 2b under optimized conditions.…”