51507-18-7Relevant 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.
HETEROCYCLIC COMPOUNDS USEFUL IN THE TREATMENT OF DISEASE
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, (2016/02/18)
Heterocyclic compounds are described that are lysophosphatidic acid receptor ligands that are useful in the treatment of lysophosphatidic acid receptor-dependent diseases and conditions, including but not limited to diseases involving fibrosis, such as fibrosis of the heart, kidney, liver and lung, and scleroderma; inflammatory diseases such as diabetic nephropathy and inflammatory bowel disease; ocular diseases such as diseases involving retinal degeneration; nerve diseases such as pruritus and pain. Non-limiting examples of those compounds include (RS)-3-Cyclopropyl-2-{4-[3-methyl-4((R)-1-phenyl-ethoxycarbonylamino)-isoxazol-5-yl]-benzyloxy}-propionic acid and (R)-1-(4′-{5-[1-(2-Chloro-phenyl)-ethoxycarbonylamino]-4-fluoro-pyrazol-1-yl}-2-fluoro-biphenyl-4-yl)-cyclopropanecarboxylic acid.
Catalytic asymmetric insertion of diazoesters into Aryl-CHO bonds: Highly enantioselective construction of chiral all-carbon quaternary centers
Gao, Lizhu,Kang, Byung Chul,Ryu, Do Hyun
supporting information, p. 14556 - 14559 (2013/10/22)
This paper describes a catalytic enantioselective route to synthesize functionalized all-carbon quaternary acyclic systems via a boron Lewis acid-promoted formal C-C insertion of diazoesters into aryl-CHO bonds. In the presence of chiral (S)-oxazaborolidinium cation 1d as a catalyst, the reaction proceeded in good yield (up to 83%) with good regioselectivity (up to 88:12) and excellent enantioselectivity (up to 99% ee). The synthetic potential of this method was illustrated by conversion of the products to both α-and β-amino esters.
