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Metallaphotoredox catalysis has emerged as a powerful platform for generating high-energy radicals from native functionalities. This approach integrates radical reactivity with transition metal catalysis to enable controlled bond formation. However, the synthesis of tertiary amines remains a significant challenge due to their redox sensitivity under photoredox conditions and the inherent difficulty of C(sp3)–N(sp3) reductive elimination. Herein, we describe a deoxygenative C–N cross-coupling between alcohols and N-hydroxylamine esters to form tertiary amines. Oxidation of the tertiary amine products is kinetically suppressed under optimized conditions, while a sterically demanding ancillary ligand promotes reductive elimination. This methodology displays broad substrate scope, accommodating diverse functional groups, heterocycles, and pharmaceutical derivatives.
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This content will become publicly available on October 20, 2026
Conjugative Radical–Radical Coupling: Transition-Metal-Free Dialkylation of Alkenes
Not AvailableAn unmet challenge in radical relay difunctionalization of alkenes is incorporation of two discrete transient radicals in a regiocontrolled manner under transition metal-free conditions. Current protocols typically rely on persistent radicals or organometallic surrogates to trap radical adducts, thereby suppressing the undesired reactions but limiting the diversity. The direct use of two transient radicals remains synthetically elusive. We present a visible-light photoredox catalyzed alkene dialkylation strategy via a kinetically guided conjugative radical-radical coupling. This transition-metal-free approach enables two direct C(sp3)−C(sp3) bond formations across the C=C double bond using alkyl and allyl or benzyl radicals. Mechanistic investigations reveal the radical nature of the process. The success of this approach hinges on kinetically controlled radical addition to alkene substrates and the steric protection of the resulting radical adducts. This mild and functional-group tolerant reaction exhibits broad substrate scope and tolerates structurally complex substrates, highlighting its potential for late-stage functionalization.
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- Award ID(s):
- 2154593
- PAR ID:
- 10656632
- Publisher / Repository:
- Chin. Chem. Soc.
- Date Published:
- Journal Name:
- CCS Chemistry
- ISSN:
- 2096-5745
- Page Range / eLocation ID:
- 1 to 12
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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