Oxidation of diazenyl-protected N-heterocycles – a new entry to functionalized lactams

Abstract

A strategy for the synthesis ofN-aryldiazenyllactams, offering the direct access to protected lactam derivatives, is based on the oxidation of the corresponding cyclic amines with a ruthenium-based catalyst in CCl4/CAN/phosphate buffer.

Evaluation of Phenyldiazenyl as a Protective/Activating Group in Lithiation–Substitution Reactions of Tetrahydroisoquinolines

“…62 63 64 Oxidation of diazinyl-protected various N -heterocycles yields the corresponding functionalized lactams. 65 Recently, visible-light-induced oxidation of diazenyl-protected THIQs has been reported by Zhang et al for the synthesis of various lactams. 66 Following our work with bis(dimethylamino)phosphinoyl 67 and 4,5-dihydrothiazoline 68 we became interested in C-1 functionalization of THIQs using phenyldiazene as the protecting group has not been explored yet.…”

Visible‐Light‐Induced Oxidation of Diazenyl‐Protected Tetrahydroisoquinolines and Isoindolines for the Synthesis of Functionalized Lactams

“…This diazenyl‐protected N ‐heterocycles can be used as valuable starting materials for the synthesis of functionalized lactams via direct α‐oxidation. In 2017, Bräse and co‐worker disclosed Ru‐catalyzed oxidation of triazene for the synthesis of functionalized lactams (Scheme 1b) [16] . However, limited substrate scope, the utilization of precious metal catalyst, hazardous inorganic oxidant and buffer solvent greatly reduced its practicality in organic synthesis.…”

“…In 2017, Bräse and co-worker disclosed Rucatalyzed oxidation of triazene for the synthesis of functionalized lactams (Scheme 1b). [16] However, limited substrate scope, the utilization of precious metal catalyst, hazardous inorganic oxidant and buffer solvent greatly reduced its practicality in organic synthesis.…”