Wang P, Yang Z, Wu T, Xu C, Wang Z, Lei A. Electrochemical Oxidative C(sp
3 )-H/N-H Cross-Coupling for N-Mannich Bases with Hydrogen Evolution.
CHEMSUSCHEM 2019;
12:3073-3077. [PMID:
30548917 DOI:
10.1002/cssc.201802676]
[Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/11/2018] [Indexed: 06/09/2023]
Abstract
N-Mannich bases are an important structure in various functional molecules. A new protocol to synthesize N-Mannich bases was established through electrochemical external-oxidant-free C(sp3 )-H/N-H cross-coupling with hydrogen evolution. Various N-methylanilines were explored in this transformation. Moreover, simple amides, heteroatom-containing amides, and succinimides were well tolerated in moderate-to-good yields. In addition, the electrochemical dehydrogenative C(sp3 )-H/N-H cross-coupling could be scaled up to 5 mmol. By using triethyl phosphite as trapping agent, the phosphorylation product was detected. At the same time, kinetic isotope effect experiments showed that the cleavage of the C-H bond is the rate-limiting step.
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