137777-31-2Relevant academic research and scientific papers
NBS-Mediated Oxygen Transfer Reaction of Carbonyl in Ester: Efficient Synthesis of Benzil–o-carboxylate Derivative From o-Alkynylbenzoate
Yuan, Si-Tian,Wang, Yan-Hua,Liu, Jin-Biao,Qiu, Guanyinsheng
supporting information, p. 1981 - 1989 (2017/06/09)
A neighbouring ester group-participated diketonization of o-alkynylbenzoate is described here for the synthesis of benzil-o-carboxylate. Application of the resulting benzil-o-carboxylate in the synthesis of quinoxalines is also reached from o-alkynylbenzoate in an one-pot fashion. This diketonization proceeds smoothly with a high regioselectivity under mild conditions. Importantly, neighbouring group plays an important role in diketonization. A plausible mechanism suggests that a bromo-incoporated isocoumarin cation is described as an intermediate, and the whole process is constituted by NBS-mediated electrophilic 6-endo annulation and oxygen transfer reaction through NBS-mediated oxidative ring-opening. Water serves as a nucleophile of ring-opening. (Figure presented.).
Synthesis of benzil-o-carboxylate derivatives and isocoumarins through neighboring ester-participating bromocyclizations of o-alkynylbenzoates
Yuan, Si-Tian,Zhou, Hongwei,Zhang, Lianpeng,Liu, Jin-Biao,Qiu, Guanyinsheng
, p. 4867 - 4874 (2017/07/10)
Bromide mediated neighboring ester-participating bromocyclizations of o-alkynylbenzoates are described here for the synthesis of benzil-o-carboxylates. 4-bromoisocoumarins are also synthesized when phenyl o-alkynylbenzoate is used as the substrate. Mechanistic studies suggest that the whole process is composed of an electrophilic bromocyclization and a dibromohydration-based ring-opening, and the neighboring ester group participates in the bromocyclization. Interestingly, the two oxygen atoms of the keto carbonyls in benzil-o-carboxylates are both derived from water. The electrophilic bromo source is in situ generated from the oxidation of bromide.
Reactivity of in situ Generated Dihalomethyllithium towards Dicarboxylic Acid Diesters and Lactones: Synthetic Applications
Barluenga, Jose,Llavona, Lujan,Yus, Miguel,Concellon, Jose M.
, p. 7875 - 7886 (2007/10/02)
The reaction of dicarboxylic acid diesters 1, with in situ generated dihalomethyllithium (1:1.4 molar ratio) at -78 deg C leads, after hydrolysis, to the corresponding dihalomethylketoesters 3.The same process using an excess of the carbenoid (1:4 molar r
