Annulation-Triggered Denitrogenative Transformations of 2-(5-Iodo-1,2,3-triazolyl)benzoic Acids

Abstract

The ability of [1,2,3]­triazolobenzoxazinones to act as a source of “hidden” diazo group was discovered. These diazo precursors can be easily prepared by the intramolecular cyclization of 2-(5-iodo-1,2,3-triazolyl)­benzoic acids. The Cu-catalyzed capture of the hidden diazo group allows for further functionalization through the denitrogenative pathway. The transformations proceed via the formation of either diazoimine or diazoamide intermediates. Novel routes to various anthranilamides as well as thiolated benzoxazinones were developed using the one-pot cyclization/diazo capture procedure.

Divergent cyclization of 2-(5-iodo-1,2,3-triazolyl)benzamides toward triazole-fused lactams and cyclic imidates

“…As a part of our ongoing studies on the preparation and reactivity of triazoles, 21 we have developed a transition metal-free approach to fused triazoles based on intramolecular S N Ar-like substitution in nucleophile-tethered 5-iodotriazoles. This route proved to be successful (Scheme 1A-7 and B) for the preparation of various triazole-fused sultams, 22 3,1-benzoxazines, 23 benzoxazinones, 24 and benzoxazoles. 25 We hypothesized that the reaction with ambident nucleophiles such as anions of secondary amides 1 can be controlled to provide both triazole-containing quinazolinones 2 and benzoxazine-imines 3 (Scheme 2).…”

Regioselective Synthesis of NO-Donor (4-Nitro-1,2,3-triazolyl)furoxans via Eliminative Azide–Olefin Cycloaddition

“…In a series of nitrogen heterocycles, 1,2,3-triazoles have become of paramount importance over the past two decades due to their universal application in diverse fields, such as drug development and medicinal chemistry [37][38][39], materials science and polymers [40,41]. In addition, they contribute to organic synthesis by acting as synthetic precursors to many valuable compounds [42][43][44]. In this regard, nitro-1,2,3-triazoles acquire additional significance due to their potential application in energetic materials science and for medicinal chemistry needs [45][46][47].…”

Domino assembly of dithiocarbamatesviaCu-catalyzed denitrogenative thiolation of iodotriazole-based diazo precursors

“…25 As a part of our current research on 1,2,3-triazole chemistry, 26 we have recently developed a new and convenient approach for the in situ generation of diazo compounds from nucleophile-tethered 5-iodotriazoles, initiated by base-promoted intramolecular substitution. 27 The annulation of an extra heterocycle in some cases proved to be a viable expedient for shifting the triazole–diazoimine equilibrium (Scheme 1C). Thus, these substrates appear to be valuable complements to other triazole-based diazo surrogates, mainly, triazolo[1,5- a ]pyridines 28 and N -sulfonyltriazoles, 29 which have been widely utilized as versatile building blocks in modern organic synthesis.…”