Iron-Catalyzed Csp²–Csp³ Cross-Coupling via Double Decarboxylation: One Step Synthesis of Remote Polar Alkenes

Abstract

Herein, we report an efficient photoinduced ironcatalyzed strategy for cross-couplings of alkyl carboxylic and acrylic acids, which provides a powerful tool for the synthesis of a variety of alkenes with polar functional groups. This novel synthetic methodology can also be applied to the preparation of ketones by using α-keto acids. Mechanistic experiments revealed preliminary mechanistic details. Diverse functionalization could be achieved, which may help streamline the synthesis of complex analogues for drug discovery.

Light-induced ligand-to-metal charge transfer of Fe(iii)-OR species in organic synthesis

“…In 2024, Zeng, Li, Rong and coworkers also used iron and copper salts as co-catalysts to achieve cross-coupling of alkyl carboxylic and acrylic acids (Scheme 15a). 23 In this case, 10 mol% of FeCl 3 ·6H 2 O and 10 mol% of Cu(acac) 2 were employed as the catalysts, together with DTBP as the oxidant. Under the conditions, cross-coupling products between alkyl carboxylic acids and aryl-substituted acrylic acids could be obtained in good yields, with tolerance of various functional groups, including ester, carbamide, ketone and ether.…”

“…Over the last five years, LMCT of iron species has been developed substantially and applied to different kinds of organic transformations. 1 f ,6–30 These studies are mainly based on LMCT of Fe( iii )-Cl and Fe( iii )-OR species. A chloride radical, which is a well-known hydrogen atom transfer (HAT) agent, can be produced in LMCT of Fe( iii )-Cl species.…”

Iron-Catalyzed Multicomponent C–H Alkylation of in Situ Generated Imines via Photoinduced Ligand-to-Metal Charge Transfer

“…Currently, significant progress has been made in the field of iron photocatalysis through LMCT processes, including hydrocarbon activation, decarboxylative functionalization, alcohol activation, and alkene azidation . Among these, the functionalization of C­(sp 3 )-H bonds in inert alkanes has garnered considerable attention in recent years as the holy grail of organic synthesis .…”