138173-74-7Relevant articles and documents
Carbanionic rearrangements of halomethylenecyclobutanes. The role of the halogen
Du, Zhengming,Haglund, Melissa J.,Pratt, Lauri A.,Erickson, Karen L.
, p. 8880 - 8887 (1998)
The carbanionic ring enlargement of (halomethylene)cyclobutanes to 1- halocyclopentenes has been extended to the fluoro analogues. At 180 °C, 3- hexyl-1-(fluoromethylene)cyclobutane provides better yields of rearranged product than the corresponding chloride, bromide, or iodide. At temperatures Br > Cl, and the fluoride does not react. Experiments with labeled substrates show that, in general, the larger the halide and the higher the reaction temperature, the greater the preference for double migration over Single migration as a mechanistic pathway. The trifluormethyl group is ineffective in promoting anionic rearrangement.
Directing-Group-Based Strategy Enabling Intermolecular Heck-Type Reaction of Cycloketone Oxime Esters and Unactivated Alkenes
Cheng, Gui-Juan,Deng, Yi,Fu, Junkai,Li, Xuexiang,Wang, Hongwei,Zhao, Chunyang,Zhou, Yu
, p. 3524 - 3530 (2020/04/30)
A new type of coupling between unactivated olefins and nonstabilized alkyl radicals was achieved, which enabled the first intermolecular Heck-type reaction of cycloketone oxime esters and unactivated alkenes. This directing-group-based strategy was compatible with various unactivated alkenes and cyclobutanone-, cyclopentanone-, and cyclohexanone-derived oxime esters. Density functional theory calculations showed that both excellent regioselectivities and good diastereoselectivities could be ascribed to the 2-butanol-assisted concerted H-OBz elimination of the conformationally strained metallacyclic transition state.
Transition-Metal-Promoted Direct C?H Cyanoalkylation and Cyanoalkoxylation of Internal Alkenes via Radical C?C Bond Cleavage of Cycloketone Oxime Esters
Lou, Jiang,He, Yuan,Li, Yunlong,Yu, Zhengkun
, p. 3787 - 3799 (2019/07/10)
Transition-metal-catalyzed alkyl-Heck-type cross-coupling of olefinic C?H bonds has been a challenge in the C?H activation area. Herein, we report FeCl3-promoted efficient direct C?H cyanoalkylation of internal alkenes, that is, ketene dithioacetals, with cycloketone oxime esters via radical C?C bond cleavage under the redox-neutral conditions. With CuCl2 as the catalyst under a dioxygen atmosphere direct C?H cyanoalkoxylation of the same internal alkenes was achieved. The cyanoalkylated tetrasubstituted alkene products could be diversely transformed to cyanoalkyl-funtionalized N- and S-heterocyclic compounds. The mechanistic studies have revealed that these C?H cyanoalkylation and cyanoalkoxylation reactions proceed through a radical pathway. (Figure presented.).
Baeyer-Villiger Oxidation of Cyclobutanones with 10-Methylacridinium as an Efficient Organocatalyst
Xu, Hua-Jian,Zhu, Feng-Fei,Shen, Yong-Ya,Wan, Xin,Feng, Yi-Si
, p. 4145 - 4151 (2012/07/27)
Baeyer-Villiger oxidation of cyclobutanones is achieved in current developed protocol with 10-methylacridinium perchlorate (AcrH +ClO4-) as a novel organocatalyst both with irradiation at room temperature and without irradiation at elevated temperature. Excellent yields of the corresponding lactones are obtained and the possible mechanism has been proposed.
