Catalyst-Controlled Regioselective Synthesis of Benzotriazlolodiazepin-7-ones and Benzotriazolodiazocin-8-ones

Abstract

A catalyst-controlled highly chemoselective and regioselective intramolecular cycloamidation of triazol-1ylbenzamides toward the synthesis of scarcely known heterocycles is reported. In the presence of a palladium catalyst, this cycloisomerization reaction afforded substituted benzotriazlolodiazepin-7-ones via intramolecular insertion of a palladium into C−C triple bond in a 7-exo-dig way. Alternatively, the use of a silver catalyst in the reaction produced substituted benzotriazolodiazocin-8-ones in a highly regioselective manner through 8-endo-dig intramolecular ring closure.

Highly Diastereoselective One-Pot Synthesis of 4,5-Dihydrofuro[2,3-b]azocin-6-one Derivatives through Cyclization/[4+4] Annulation Reactions

“…In order to overcome the shortcomings of previous access to furan-fused azocine derivatives, and continue our efforts to exploring new one-pot strategies for the elaboration of heterocycles, , we designed a novel one-pot synthesis of furo­[2,3- b ]­azocin-6-one derivatives through a cyclization/[4+4] annulation reaction of enyne-amides and ynones (Scheme ). There are several challenges for this new transformation, including the control of the stereochemistry, the regioselectivity of the annulation (formation of 3 vs I ), and the selective [4+4] annulation instead of [4+2] cycloaddition (formation of 3 vs II/III ) …”

Reagent-Based Diversity-Oriented Synthesis of Triazolo[1,5-a][1,4]diazepine Derivatives from Polymer-Supported Homoazidoalanine

“…Derivatives bearing triazolo­[1,5- a ]­[1,4]­diazepine scaffolds (triazolodiazepines hereafter) are practically unexplored groups of heterocycles. In contrast to analogous triazolobenzodiazepinones, which have been prepared in different ways, − the synthesis of triazolodiazepines has rarely been reported. The original approach was published in 2011 by Buysse et al In our recent contribution, we have developed an alternative methodology based on solid-phase synthesis (SPS), starting from immobilized amino acids and using Fmoc-azidoalanine as the key building block.…”

Copper‐Free Solid‐Phase Synthesis of Triazolo[1,5‐a][1,4]diazepin‐6‐ones

“…Recently, we developed a solid‐phase synthesis method for triazolobenzodiazepinones based on the spontaneous AAC of immobilized propargyl‐azidobenzamides [9] . The preparation of triazolobenzodiazepinones was also reported by others using different approaches [10–15] . In contrast, the synthesis of parent triazolodiazepinones has rarely been studied.…”