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N-Heterocyclic carbene-catalyzed deaminative cross-coupling of aldehydes with Katritzky pyridinium salts.

ABSTRACT: By employing an N-heterocyclic carbene (NHC) catalyst, we developed a versatile catalytic system that enables deaminative cross-coupling reactions of aldehydes with redox-active pyridinium salts. Katritzky pyridinium salts behave as single-electron oxidants capable of generating alkyl radicals enabled by the redox properties of the enolate form of Breslow intermediates. The resultant alkyl radical undergoes efficient recombination with the NHC-bound aldehyde-derived carbonyl carbon radical for the formation of a C-C bond. The mild and transition metal-free reaction conditions tolerate a broad range of functional groups, and its utility has been further demonstrated by the modification of a series of peptide feedstocks and application to the three-component dicarbofunctionalization of olefins.

PROVIDER: S-EPMC8157273 | BioStudies |

REPOSITORIES: biostudies

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Catalyst-Free Deaminative Functionalizations of Primary Amines by Photoinduced Single-Electron Transfer.

Project description:The use of pyridinium-activated primary amines as photoactive functional groups for deaminative generation of alkyl radicals under catalyst-free conditions is described. By taking advantage of the visible light absorptivity of electron donor-acceptor complexes between Katritzky pyridinium salts and either Hantzsch ester or Et3 N, photoinduced single-electron transfer could be initiated in the absence of a photocatalyst. This general reactivity platform has been applied to deaminative alkylation (Giese), allylation, vinylation, alkynylation, thioetherification, and hydrodeamination reactions. The mild conditions are amenable to a diverse range of primary and secondary alkyl pyridiniums and demonstrate broad functional group tolerance.

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Photoredox-Catalyzed Deaminative Alkylation via C-N Bond Activation of Primary Amines.

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Deaminative Arylation of Amino Acid-derived Pyridinium Salts.

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