Oxyarylation and Aminoarylation of Styrenes Using Photoredox Catalysis

Abstract

A three-component coupling of styrenes is reported, using photoredox catalysis to achieve simultaneous arylation and C-O or C-N bond formation across the styrene double bond.

Three‐Component Azidation of Styrene‐Type Double Bonds: Light‐Switchable Behavior of a Copper Photoredox Catalyst

“…In contrast to our previous PRC arylation system, [11] Ritter-type reactivity of nitrile components was not observed under these reaction conditions.A s aresult, we could use MeCN as asolvent for the reaction and successfully use simple inorganic salts as alternatives to oxygen nucleophiles.U se of NaN 3 in combination with 1 resulted in double azidation in excellent yield (4a). The synthesis of the a-bromo azide 5 was also possible in moderate yield, thus providing au seful substrate for further synthetic manipulation.…”

“…[11] We began our investigation using 5equivalents of styrene (2a)a nd 1 as the limiting reagent, and 1mol %o faphotoredox catalyst in methanol as the solvent of choice (Table 1). Interestingly,t he commonly used [Ir(ppy) 3 ]a nd [Ru-(bpy) 3 Cl 2 ]p hotoredox catalysts failed to deliver any product in appreciable yields (entries 1a nd 2).…”

Light on Unsaturated Hydrocarbons – “Gotta Heterofunctionalize Them All”

“…Greaney and coworkers expanded the same reaction to a different radical precursor. [39] A hypervalent iodine reagent can be converted into a C-centered radical by a photoredox catalytic system. They reported two examples of the carboamidation of styryl derivatives by this method.…”

Synthesis of 6‐Alkylated Phenanthridine Derivatives Using Photoredox Neutral Somophilic Isocyanide Insertion

“…While the palladium-catalyzed isocyanide insertions often require high reaction temperatures and have the tendency to undergo multiple consecutive insertions, [5] the use of isocyanides as somophiles for insertion reactions holds promise for practical synthetic applications under mild reaction conditions. [6] As a convenient approach to generate somophiles, photoredox catalysis, [7] which usually introduces alkenes, [8] alkynes, [9] and aromatic rings [10] as radical acceptors, has been widely used in the synthetic community to construct C À C bonds since 2008. [11] However, none of the reported work has employed photoredox catalysis to initiate isocyanide insertion.…”

“…The complex [fac-Ir(ppy) 3 ] (A) was chosen as the photocatalyst because of its superior oxidation capacity in the excited state. [7,8] When a solution of 1 a and 2 a in CH 2 Cl 2 was irradiated with a 3 W blue LED in the presence of A and Na 2 HPO 4 for 10 hours, the desired phenanthridine 3 a was isolated in 25 % yield ( DMSO, and MeOH as solvents gave less than 70 % yield (entries 2-4). To our delight, a 92 % yield was achieved when DMF was used as the solvent (entry 5).…”