Divergent functionalization of aldehydes photocatalyzed by neutral eosin Y with sulfone reagents

Yan, Jianming; Tang, Haidi; Kuek, Eugene Jun Rong; Shi, Xiangcheng; Liu, Chenguang; Zhang, Muliang; Piper, Jared L.; Duan, Shengquan; Wu, Jie

doi:10.1038/s41467-021-27550-8

Cited by 61 publications

(18 citation statements)

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“…The use of peroxides as oxidants for the thermal formation of the acyl radical is a popular method, although more modern protocols generate it via photoredox catalysis. [145,146] In 2016, Satyanarayana and Suchand [147] reported the Pdcatalyzed coupling between iodoarenes and aldehydesincluding furfural -in the presence of tert-butyl hydroperoxide (TBHP), to afford the corresponding ketones. As to the mechanism, the authors propose an initial oxidative addition of in situ formed Pd(0) complex onto the ArÀ I bond.…”

Section: Furoylation Via Acyl Radicalsmentioning

confidence: 99%

C−H Activation Based Functionalization of Furfural Derivatives

et al. 2022

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Dedicated to Professor Cesare Gennari on the occasion of his 70th birthday.Furfural and related compounds are building blocks of industrial interest, obtained from raw biomass. Their use as precursors of basic and fine chemicals has gained increasing attention as a green alternative to petroleum-derived compounds. Several works have reported the functionalization of furfurals to obtain a wider range of chemicals, opening up new synthetic possibilities and applications, ranging from biofuels to pharmaceuticals. Among these works, processes based on CÀ H activation are the most attractive ones for their atom economy and the possibility to use non-activated substrates. This minireview summarizes the reported methods of direct CÀ H functionalization of furfurals without prior modification of the redox state of the aldehyde function. In particular, the transition metal catalyzed functionalization of each bond of the heteroaromatic nucleus of these molecules is systematically discussed, as well as examples of CÀ H transformations of the aldehyde function.

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Section: Furoylation Via Acyl Radicalsmentioning

confidence: 99%

C−H Activation Based Functionalization of Furfural Derivatives

et al. 2022

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“…Very recently, the Ye group realized a HAT process for hydroalkylation of unactivated olefins using amine-boranes under photoredox catalysis . In line with our ongoing interest in visible light-induced transformations using gaseous reagents as feedstocks and fluoroalkylation reactions, we hypothesized that a photoredox-induced ligated boryl radical may trigger either XAT or HAT with ClCF 2 H to produce the corresponding active radical, which can participate in subsequent transformations. We herein report the successful execution of a XAT process with ClCF 2 H instead of a HAT process using amine-boryl radicals for difluoromethylation of unactivated alkenes in a metal-free fashion, which can be applied for LSF of pharmaceutical compounds and natural products (Figure D).…”

Section: Introductionmentioning

confidence: 96%

Difluoromethylation of Unactivated Alkenes Using Freon-22 through Tertiary Amine-Borane-Triggered Halogen Atom Transfer

et al. 2022

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The application of abundant and inexpensive fluorine feedstock sources to synthesize fluorinated compounds is an appealing yet underexplored strategy. Here, we report a photocatalytic radical hydrodifluoromethylation of unactivated alkenes with an inexpensive industrial chemical, chlorodifluoromethane (ClCF2H, Freon-22). This protocol is realized by merging tertiary amine-ligated boryl radical-induced halogen atom transfer (XAT) with organophotoredox catalysis under blue light irradiation. A broad scope of readily accessible alkenes featuring a variety of functional groups and drug and natural product moieties could be selectively difluoromethylated with good efficiency in a metal-free manner. Combined experimental and computational studies suggest that the key XAT process of ClCF2H is both thermodynamically and kinetically favored over the hydrogen atom transfer pathway owing to the formation of a strong boron–chlorine (B–Cl) bond and the low-lying antibonding orbital of the carbon–chlorine (C–Cl) bond.

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“… 20 We have developed direct HAT photocatalysis with aldehydes to access the corresponding acyl radicals, which could participate in a series of useful transformations such as asymmetric 1,4-addition with Michael acceptors, 21 radical Smiles rearrangements, 22 and nucleophilic substitution reactions with sulfone reagents. 23 Among the reported photo-HAT catalysts, tetrabutylammonium decatungstate (TBADT) catalytically cleaves the aldehydic C–H bond under near-UV light irradiation, giving rise to acyl radicals and TBADT–H species. 24 We envisioned that the TBADT–H species generated in situ could be regarded as an analogue of transition metal-hydrides, 25 which could trigger the reduction of nitroarenes, realizing reductive coupling of nitroarenes with aldehydes ( Fig.…”

Section: Introductionmentioning

confidence: 99%