Chitoor Sivaramakrishnan Venkatachalam

Bio: Chitoor Sivaramakrishnan Venkatachalam is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Radical & Radical cyclization. The author has an hindex of 1, co-authored 2 publications receiving 18 citations.

Cathodic reduction of N-(2-iodophenyl)-N-alkylcinnamides: a novel sequential electrochemical radical cyclisation and hydroxylation

Abstract: In recent years, intramolecular aryl radical cyclisation has emerged as a useful route for the synthesis of benzannulated heterocycles and carbocycles. The aryl radicals are generated in situ from aryl halides (iodides or bromides) with tributylstannyl hydride–AIBN, SmI2, Co(I) or under photochemical conditions. The present work envisages the generation of aryl radicals by cathodic reduction of the carbon–iodine bond of N-(2-iodophenyl)-N-alkylcinnamides and their intramolecular cyclisation. The cathodic reduction of N-(2-iodophenyl)-N-alkylcinnamides under deaerated conditions in DMF gave 1-alkyl-3-benzylindolin-2-ones regioselectively and in the presence of oxygen yielded surprisingly 1-alkyl-3-hydroxy-3-benzylindolin-2-ones. Both these products were formed by a 5-exo-trig process in good yields. A mechanism for the formation of the products has been proposed through the use of cyclic voltammetry, coulometry and controlled-potential electrolysis as well as deuterium labelling.

Electrochemical strategies for C-H functionalization and C-N bond formation.

Abstract: Conventional methods for carrying out carbon–hydrogen functionalization and carbon–nitrogen bond formation are typically conducted at elevated temperatures, and rely on expensive catalysts as well as the use of stoichiometric, and perhaps toxic, oxidants. In this regard, electrochemical synthesis has recently been recognized as a sustainable and scalable strategy for the construction of challenging carbon–carbon and carbon–heteroatom bonds. Here, electrosynthesis has proven to be an environmentally benign, highly effective and versatile platform for achieving a wide range of nonclassical bond disconnections via generation of radical intermediates under mild reaction conditions. This review provides an overview on the use of anodic electrochemical methods for expediting the development of carbon–hydrogen functionalization and carbon–nitrogen bond formation strategies. Emphasis is placed on methodology development and mechanistic insight and aims to provide inspiration for future synthetic applications in the field of electrosynthesis.

The Generation of Aryl Anions by Double Electron Transfer to Aryl Iodides from a Neutral Ground-State Organic Super-Electron Donor

Abstract: Stabilized carbanions can be prepared by deprotonation of the corresponding carbon acids, but more reactive carbanions, such as aryl anions, are usually made by metal–halogen exchange or by electrochemical routes.[1] Whereas the use of metals and organometallic compounds to form aryl anions is well established, the use of totally organic electron-transfer agents, in the absence of photochemical activation, is completely unknown.[2] Herein we report the first neutral organic molecule to achieve this feat.