Oxidative Functionalizations Using Hypervalent Iodine Reagents

Abstract

Hypervalent iodine reagents are valuable reagent in synthetic organic chemistry. newlineThese reagents play a key role in replacing the toxic heavy metal reagents because of newlinetheir mild reaction condition and environmentally friendly nature. In earlier days, hypervalent newlineiodine reagents were mainly known for oxidative properties but scope of these newlinereagents is not limited to oxidation reaction; they also act as excellent electrophile and newlinebecause of electrophilic nature these reagents are mainly used in many of the organic newlinetransformation reactions. Within the frame of our studies, we have performed various newlineoxidative transformations using hypervalent iodine reagents in stoichiometric amount newlineand as a catalyst. newlineThe cyclic iodine(III) reagent trifluoromethyl-3-oxo-1_3,2-benziodoxole-1(3H)- newlinecarboxylate has been synthesized efficiently in single step and used as an oxidant in the newlineoxidation of organosulfides to organosulfones. Next, the synthesis of _-cyanoepoxides newlinewas achieved through epoxidation of _-cyanostyrenes using PIDA as oxidant. Further newlinein continuation with this work, similar reactions were performed using iodoarenes newlineas precatalyst in presence of Oxone and trifluoroacetic acid as an oxidative system. newlineThe synthesis of benzofurans were achieved by the cyclization of 2-hydroxystilbenes newlineusing PIDA as catalyst and through in situ generation of iodine(III) active species using newlineiodoarene as precatalyst and mCPBA-CF3COOH as oxidative system. The synthesis newlineof 11-aryl-6H-isoindolo[2,1-a]indol-6-ones a tetracyclic fused indoles were also newlineachieved through the cyclization of 2-(1-arylethynyl)benzamides using PhI as precatalyst, newlinemCPBA as oxidant and trifluoroacetic acid as additive in TFE solvent. Further, we newlinehave developed an efficient approach for the selenenylation of alkenes using in situ generated newlinehypervalent iodine active species as an oxidative agent and diphenyl diselenide. newlineThe selenenylation of _-oxoketenedithioacetals were performed using iodobenzene as newlineprecatalyst, mCPBA as a co-oxidant, AcOH as an additive and Ph2Se2 as so