Formation of Hybrid Ring Structure of Cyanurate/Isocyanurate in the Reaction be-tween 2,4,6-Tris(4-Phenyl-Phenoxy)-1, 3,5-Triazine and Phenyl Glycidyl Ether

Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.

Photoredox Catalysis Unlocks the Nickel-Catalyzed Cyanation of Aryl Halides under Benign Conditions

The transition-metal-catalyzed cyanations of aryl halides are among the most used methods for synthesizing aryl nitriles.Despite tremendous advances,cyanating an aryl halide in a facile and benign fashion has generally been unsuccessful.The challenge in this significant transformation is the strong affinity of cyanide for metals,which hampers oxidative addition(OD)and reductive elimination(RE)making organometallic catalysis elusive.Herein,we demonstrate for the first time that photoredox-nickel-catalyzed cyanations of aryl halides are readily enabled by visible light,in which Ni(Ⅱ)species are transiently oxidized to Ni(Ⅲ)species,thereby facilitating subsequent cyanide transfer and RE.Using this dual catalysis strategy,we cyanated aryl and alkenyl halides at room temperature in a highly benign manner(30 examples,53-93% yield)by avoiding the use of air-sensitive ligands,Ni(0)precursors,and hypertoxic cyanation reagents,while also limiting excess metal waste.Computational studies were also used to help understand the present transformation.

N-Heterocyclic Carbene-Catalysed Direct Synthesis of Cyano Esters via Cyanation-Esterification Reaction of a-Keto Esters

The cyanation-esterification reaction of a-keto esters catalysed by N-heterocyclic carbenes （NHCs） is developed Under the catalysis of 10 tool% 1,3-bis（2,6-diisopropylphenyl）imidazol-2-ylidene, aromatic and aliphatic a-keto esters reacted with ethyl cyanoformate or acetyl cyanide to produce the corresponding cyano esters with a tetra- substituted carbon center in high yields.

A facile synthesis of cyano-chlorins related to chlorophyll from formyl (pyro)-pheophorbide-a by a tandem transformation of the aldehyde into a nitrile group

A facile synthesis for cyanochlorin related to chlorophyll from a formyl-substituted chlorin, by the oxidation of methyl （pyro）pheophorbide-a, was accomplished. These readily available chlorin aldehydes were assembled together with hydroxylamine hydrochloride in a tandem process to produce the corresponding chlorin nitriles in moderate to good yields. The formation of chlorin nitrile was discussed and a possible mechanism for the corresponding cyanation reaction was tentatively proposed.