Recent Advances in Intramolecular Metal‐Free Oxidative C–H Bond Aminations Using Hypervalent Iodine(III) Reagents

Abstract

Hypervalent iodine chemistry is a rapidly growing area of research with tremendous impact on synthetic chemistry in the past years. A rich and diverse chemistry is now available for reactions using hypervalent iodine reagents, as metal‐free, ecofriendly reagents and the advent of new reactions will be of large benefit to researchers working in the area of selective synthesis. In this review article, we emphasize the usage of hypervalent iodine(III) reagents for metal‐free intramolecular oxidative C–N bond formation/annulation to synthesize wide range of N‐heterocycles in organic synthesis. The functionalization of C–H bonds through the involvement of sp‐, sp2‐, and sp3‐hybridized carbon atoms for cyclizations is discussed in detail.

Nitrenium Ions from Amine‐Iodine(III) Combinations

“…The development of suitable methods for C−N bond formation is one of the most targeted research areas in organic synthesis . Significant effort has been directed towards developing sustainable oxidative C−N bond formation methods using iodine(III) chemistry . Nitrenium ion chemistry with iodine(III) reagents has been well explored for C−N bond formation reactions.…”

Alkene Difunctionalization Using Hypervalent Iodine Reagents: Progress and Developments in the Past Ten Years

“…Aside from transition metal chemistry, hypervalent iodine itself has the aforementioned properties suitable for application in a diverse range of organic transformations. Consequently, over the past two decades, there have been several general reviews [1,2,3,4,5,6,7,8,9,10], books and book chapters [11,12,13], and specialized reviews [14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29] in this regard. In this review, we hence focus on progress and developments that have taken place in the past 10 years in the field of alkene difunctionalization such as diamination, aminofunctionalization, diacetoxylation, oxyfunctionalization, and dihalogenation reactions.…”

Micelle‐Enabled One‐Pot Guanidine Synthesis in Water Directly from Isothiocyanate using Hypervalent Iodine(III) Reagents under Mild Conditions

“…Recently, hypervalent iodine have received much attention as oxidants due to their environmentally friendly character, ease of handling, selectivity and reasonable cost . Because of the broad synthetic potential of hypervalent iodine, IBX (2‐Iodoxybenzoic acid) have been reported as desulfurization agents for guanidine synthesis from thiourea .…”

“…Recently,h ypervalent iodine have received much attention as oxidants due to their environmentally friendly character, ease of handling, selectivity and reasonable cost. [61][62] Because of the broad synthetic potentialo fh ypervalent iodine, IBX (2-Iodoxybenzoic acid) have been reported as desulfurization agents for guanidine synthesis from thiourea. [63] However,f or non-metal mediated guanidine synthesis including IBX, requiresatwo-stepp rocess from isocyanate (3)a nd the use of organic solvent as medium in combination with stoichiometric organic amine base are required.F rom green chemistry perspective, the use of harmful organic solvent/base and multiple-step process would increase the operating cost and risk in large scale production.…”