126191-07-9Relevant articles and documents
Catalytic Asymmetric Homologation of Ketones with α-Alkyl α-Diazo Esters
Tan, Fei,Pu, Maoping,He, Jun,Li, Jinzhao,Yang, Jian,Dong, Shunxi,Liu, Xiaohua,Wu, Yun-Dong,Feng, Xiaoming
, p. 2394 - 2402 (2021/02/16)
The homologation of ketones with diazo compounds is a useful strategy to synthesize one-carbon chain-extended acyclic ketones or ring-expanded cyclic ketones. However, the asymmetric homologation of acyclic ketones with α-diazo esters remains a challenge due to the lower reactivity and complicated selectivity. Herein, we report the enantioselective catalytic homologation of acetophenone and related derivatives with α-alkyl α-diazo esters utilizing a chiral scandium(III) N,N′-dioxide as the Lewis acid catalyst. This reaction supplies a highly chemo-, regio-, and enantioselective pathway for the synthesis of optically active β-keto esters with an all-carbon quaternary center through highly selective alkyl-group migration of the ketones. Moreover, the ring expansion of cyclic ketones was accomplished under slightly modified conditions, affording a series of enantioenriched cyclic β-keto esters. Density functional theory calculations have been carried out to elucidate the reaction pathway and possible working models that can explain the observed regio- and enantioselectivity.
Enantioselective synthesis of α-alkyl-β-ketoesters: Asymmetric Roskamp reaction catalyzed by an oxazaborolidinium ion
Gao, Lizhu,Kang, Byung Chul,Hwang, Geum-Sook,Ryu, Do Hyun
supporting information; experimental part, p. 8322 - 8325 (2012/09/08)
Breaking kamp: A catalytic route toward chiral α-alkyl-β- ketoesters using the title reaction of α-alkyl diazoester with aldehydes has been developed (see scheme). The reaction proceeds with high to excellent enantioselectivities and this methodology was applied to a concise two-step synthesis of the natural pheromone sitophilate. Copyright
Catalytic asymmetric roskamp reaction of α-Alkyl-α-diazoesters with aromatic aldehydes: Highly enantioselective synthesis of α-Alkyl-β-keto esters
Li, Wei,Wang, Jun,Hu, Xiaolei,Shen, Ke,Wang, Wentao,Chu, Yangyang,Lin, Lili,Liu, Xiaohua,Feng, Xiaoming
supporting information; experimental part, p. 8532 - 8533 (2010/08/06)
The first catalytic enantioselective Roskamp reaction of α-alkyl-α-diazoesters with aromatic aldehydes was realized using a simple chiral N, N′-dioxide-scandium(III) complex. Remarkably, with 0.05 mol % catalyst, the reaction was performed well over a series of substrates, giving the desired products chemoselectively in excellent yields (up to 99%) and enantioselectivities (up to 98% ee) under mild conditions. This protocol provides a promising method for the synthesis of chiral α-alkyl-β- keto esters and 1,3-diols.
