Decarboxylative Anti-Michael Addition to Olefins Mediated by Photoredox Catalysis

Abstract

Decarboxylative coupling of carboxylic acids with activated olefins has been accomplished using visible light photoredox catalysis. The strategic placement of a radical-stabilizing aromatic group at the β-position of the olefin component biases the regioselectivity of the addition, allowing reliable, facile access to anti-Michael-type products from readily available precursors. The scope of this methodology was demonstrated with a range of carboxylic acids and appropriately substituted olefins and was applied toward a two-step synthesis of the antiarrhythmic agent encainide.

Synthesis of Novel 2-(Het)arylpyrrolidine Derivatives and Evaluation of Their Anticancer and Anti-Biofilm Activity

“…Various cross-coupling reactions of (hetero)aromatics with appropriately substituted pyrrolidine derivatives [12,13,14,15,16,17], including oxidative [18,19,20] and photooxidative ones [21,22,23,24], are the most often used within this pathway. In several cases, the synthesis of enantiomerically pure 2-(het)arylpyrrolidines has been also accomplished by decarboxylative (hetero)arylation of proline derivatives [25,26,27,28,29,30,31]. The second approach is based on the formation of a pyrrolidine ring from acyclic precursors.…”

Acid‐Catalyzed Intramolecular Imination / Nucleophilic Trapping of 4‐Aminobutanal Derivatives: One‐Pot Access to 2‐(Pyrazolyl)pyrrolidines

“…Various cross‐coupling reactions of heteroaromatics with appropriately substituted pyrrolidine derivatives, including oxidative and photooxidative ones, are the most often used within this pathway. Synthesis of enantiomerically pure 2‐(hetaryl)pyrrolidines in several cases has also been accomplished by decarboxylative heteroarylation of proline derivatives …”

Catalytic Intermolecular Dicarbofunctionalization of Styrenes with CO2 and Radical Precursors

“…[27] As shown in Scheme 4, this turned out to be the case.S pecifically,w ef ound that difluoromethyl-containing phenyl acetic acids are easily within reach when using CHF 2 SO 2 Na under otherwise identical reaction conditions to those shown for CF 3 SO 2 Na (4a-c). [27] As shown in Scheme 4, this turned out to be the case.S pecifically,w ef ound that difluoromethyl-containing phenyl acetic acids are easily within reach when using CHF 2 SO 2 Na under otherwise identical reaction conditions to those shown for CF 3 SO 2 Na (4a-c).…”

“…In light of these results,wewondered whether our redoxneutral dicarbofunctionalization reaction of styrenes with CO 2 could be extended to radical precursors other than CF 3 SO 2 Na. [27] As shown in Scheme 4, this turned out to be the case.S pecifically,w ef ound that difluoromethyl-containing phenyl acetic acids are easily within reach when using CHF 2 SO 2 Na under otherwise identical reaction conditions to those shown for CF 3 SO 2 Na (4a-c). In light of these results, we questioned whether nonfluorinated radical analogues could also be used for similar purposes.I ndeed, we found that easily accessible benzyl trifluoroborates (E ox =+1.1 Vvs.…”