An Expedient Radical Approach for the Decarboxylative Synthesis of Stereodefined All‐Carbon Tetrasubstituted Olefins

• Published in: Angewandte Chemie International Edition Vol. 63; no. 26; pp. e202403651 - n/a
• Main Authors: Zeng, Qian, Nirwan, Yamini, Benet‐Buchholz, Jordi, Kleij, Arjan W.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 21.06.2024; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Alkenes; Amines; Carbon dioxide; Carbonates; Chemistry; Chemistry, Multidisciplinary; Decarboxylation; Homogeneous Catalysis; Olefins; Photocatalysis; Physical Sciences; Precursors; Protonation; Radical Chemistry; Science & Technology; Substrates; Homogeneous Catalysis; CATALYSIS; Amines; PHOTOREDOX; Olefins; Photocatalysis; TAMOXIFEN; Radical Chemistry; ALKYNES; ALKENES; RECENT PROGRESS; STEREOSELECTIVE-SYNTHESIS; TRIFLUOROMETHYLATION
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202403651

We report a user‐friendly approach for the decarboxylative formation of stereodefined and complex tri‐ and tetra‐substituted olefins from vinyl cyclic carbonates and amines as radical precursors. The protocol relies on easy photo‐initiated α‐amino‐radical formation followed by addition onto the double bond of the substrate resulting in a sequence involving carbonate ring‐opening, double bond relay, CO2 extrusion and finally O‐protonation. The developed protocol is efficient for both mismatched and matched polarity substrate combinations, and the scope of elaborate stereodefined olefins that can be forged including drug‐functionalized derivatives is wide, diverse and further extendable to other types of heterocyclic and radical precursors. Mechanistic control reactions show that the decarboxylation step is a key driving force towards product formation, with the initial radical addition under steric control. A radical‐based, photo‐catalyzed decarboxylative formation of stereodefined tri‐ and tetrasubstituted olefins is reported using various α‐amino radical precursors and heterocycles as substrates. This user‐friendly protocol combines a wide structural scope, easy drug and postsynthetic manipulations, and variation in both reaction partners. The mechanistic studies reveal a key CO2 extrusion step to enable the overall transformation.