Electrophotocatalytic tri- or difluoromethylative cyclization of alkenes

Abstract

We describe an electrophotocatalytic tri- or difluoromethylation/cyclization cascade of alkenes with fluoromethanesulfinate salts. This external-oxidant-free oxidative cyclization proceeds under mild electrode potentials yet is robust, and it is applicable to...

Photoredox-catalyzed intramolecular oxy- and aminoacylation of alkenes with acyl oxime esters: facile synthesis of acylated saturated heterocycles

“…Among them, radical-initiated cascade cyclizations of alkenes equipped with pendant heteroatom-containing nucleophiles, which not only allow the synthesis of saturated heterocyclic frameworks but also enable the simultaneous introduction of valuable functional groups via a one-pot process, could provide streamlined and facile synthetic protocols to access structurally diverse heterocycles. 4 In this regard, in particular, the acyl radical-triggered transformation has emerged as a hot research topic due to the potential derivatization applications of the acyl substituent in heterocyclic compounds. 5 To date, several common carbonyl compounds including aromatic aldehydes, 6 carboxylic acids, 7 anhydrides, 8 acyl chlorides, 9 α-ketocarboxylic acids, 10 and other acyl sources 11 have been widely utilized in a series of acyl-radical-involved transformations.…”

Electrochemical Radical Tandem Difluoroethylation/Cyclization of Unsaturated Amides to Access MeCF2-Featured Indolo/Benzoimidazo [2,1-a]Isoquinolin-6(5H)-ones

“…However, recent developments in this direction have always involved peroxides or photoredox catalysts [ 12 , 13 , 14 , 15 , 16 ]. On the other hand, electrochemical synthesis has also attracted much attention due to the advantages of avoiding the usage of chemical oxidants and reductants [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Very recently, much progress in electrochemical difluoroethylation has been made by Hu [ 24 ] and our group [ 25 , 26 ].…”

Photo‐Induced Difluoromethylation‐Cyclization of Indoles Using Tetrazole Sulfone Reagent Under Visible Light

“…[4] The cascade radical addition/cyclization of N-alkene tethered indoles has been proved as a convenient route towards the polycyclic indoles. [5] A viarety of radical species such as trichloromethyl radical (•CCl 3 ), [6] sulfonyl radical (Ts•), [7] phosphite radical(•PO(OEt) 2 ) [8] were explored to construct the pyrrolo [1,2-a]indoles under copper, [9] palladium, [10] nickel, [11] silver, [12] metal-free, [13] peroxides, [6] electrochemical synthesis [14] and photocatalysis. [8a,15] In most cases, an electron-withdrawing group at the C3 position was required.…”