Bio-inspired Halogen Bonding-Promoted Cross Coupling for the Synthesis of Organoselenium Compounds

Abstract

Noncovalent interactions play fundamental roles in many organic and biochemical processes, including hydrogen and halogen bonding, which are vital in the fields of synthesis and catalysis. Herein, we describe the application of halogen bonding interactions to facilitate the reaction balance between an electron donor–acceptor (EDA) complex and Ph2Se2 for the synthesis of a series of organoselenium compounds. The EDA complex concept has recently emerged as an attractive path for visible light-induced transformations due to facile reaction conditions and the avoidance of photocatalysts. Density functional theory calculations reveal that an iodine–π* interaction leads to the formation of an alkyl radical from the N-(acyloxy)­phthalimide ester. The resulting alkyl radical is captured by the diselenide–I• complex to form the C–Se bond. The developed selenide synthesis strategy has been applied in the transformation of primary, secondary, and tertiary carboxylic acids as well as a series of natural products, drugs, and α-selenoamino acids.

Visible Light‐Induced Photoredox and Copper‐Catalyzed C−N Cross‐Coupling: A Mechanistic Perspective

“…[53,54] This led to the realization that electron transfer to aliphatic redox-active esters would yield alkyl radicals via controlled radical decarboxylation. [55][56][57] It was inferred that electron transfer from sodium iodide to N-(cyclohexanecarbonyl)phthalimide is endergonic but in the presence of triphenylphosphine (PPh 3 ) feasible formation of the Ph 3 PÀ I * radical was observed employing DFT calculations. [52,58] Thus, a combination of triphenylphosphine and sodium iodide plays the role of a photocatalyst for the decarboxylative alkylation reaction.…”

Exploring Tunable Properties, Solvent-Modulated Dynamics, and Novel C(sp3)–H Activation Mechanisms in Electron Donor–Acceptor Complexes

“…First, the process of light absorption and the subsequent initiation of chemical reactions remain unclear . Additionally, understanding how noncovalent interactions influence the reactivity of EDA complexes is imperative. , Lastly, the nature of the solvent plays a crucial role in processes involving electron transfer . As a paradigm shown in Scheme , several groups reported a direct photochemical thiolation of C­(sp3)–H bond-containing etheric, allylic, and benzylic substrates through an EDA complex formed between thiophenol and iodobenzene, facilitated by halogen bonding interactions .…”