Zhang JW, Wang YR, Pan JH, He YH, Yu W, Han B. Deconstructive Oxygenation of Unstrained Cycloalkanamines.
Angew Chem Int Ed Engl 2020;
59:3900-3904. [PMID:
31869508 DOI:
10.1002/anie.201914623]
[Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/18/2019] [Indexed: 12/20/2022]
Abstract
A deconstructive oxygenation of unstrained primary cycloalkanamines has been developed for the first time using an auto-oxidative aromatization promoted C(sp3 )-C(sp3 ) bond cleavage strategy. This metal-free method involves the substitution reaction of cycloalkanamines with hydrazonyl chlorides and subsequent auto-oxidative annulation to in situ generate pre-aromatics, followed by N-radical-promoted ring-opening and further oxygenation by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and m-cholorperoxybenzoic acid (mCPBA). Consequently, a series of 1,2,4-triazole-containing acyclic carbonyl compounds were efficiently produced. This protocol features a one-pot operation, mild reaction conditions, high regioselectivity and ring-opening efficiency, broad substrate scope, and is compatible with alkaloids, osamines, and peptides, as well as steroids.
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