36025-15-7Relevant academic research and scientific papers
Reactivity of substrates with multiple competitive reactive sites toward NBS under neat reaction conditions promoted by visible light
Grjol, Bla?,Jereb, Marjan
, p. 5235 - 5248 (2021/06/07)
Regioselectivity of visible-light-induced transformations of a range of (hetero)aryl alkyl-substituted ketones bearing several competitive reactive sites (α-carbonyl, benzyl and aromatic ring) with N-bromosuccinimide (NBS) was studied under solvent-free reaction conditions (SFRC) and in the absence of inert-gas atmosphere, radical initiators and catalysts. An 8-W energy-saving household lamp was used for irradiation. Heterogeneous reaction conditions were dealt with throughout the study. All substrates were mono- or dibrominated at the α-carbonyl position, and additionally, some benzylic or aromatic bromination was observed in substrates with benzylic carbon atoms or electron-donating methoxy groups, respectively. Surprisingly, ipso-substitution of the acyl group with a bromine atom took place with (4-methoxynaphthyl) alkyl ketones. While the addition of the radical scavenger TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxy) decreased the extent of α- and ring bromination, it completely suppressed the benzylic bromination and α,α-dibromination with NBS under SFRC.
Access to α-Cyano Carbonyls Bearing a Quaternary Carbon Center by Reductive Cyanation
Ren, Xinyi,Shen, Chaoren,Wang, Guangzhu,Shi, Zhanglin,Tian, Xinxin,Dong, Kaiwu
supporting information, p. 2527 - 2532 (2021/05/05)
Reductive cyanation of tertiary alkyl bromides using electrophilic cyanating reagent and zinc reductant was developed, providing various α-cyano ketones, esters, and carboxamides containing a nitrile-bearing all-carbon quaternary center in good to excellent yields under mild reaction conditions. The corresponding reaction mechanism involving in situ generated organozinc reagent and reactivity distinction was elucidated by density functional theory computation.
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
Chen, Wenxin,Liu, Zheng,Tian, Jiaqi,Li, Jin,Ma, Jing,Cheng, Xu,Li, Guigen
supporting information, p. 12312 - 12315 (2016/10/07)
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h-1 turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry was used to synthesize a common precursor of a class of hydroxysteroid dehydrogenase inhibitors.
Discovery of 6-phenylpyrimido[4,5- B ][1,4]oxazines as potent and selective Acyl CoA: Diacylglycerol acyltransferase 1 (DGAT1) inhibitors with in vivo efficacy in rodents
Fox, Brian M.,Sugimoto, Kazuyuki,Iio, Kiyosei,Yoshida, Atsuhito,Zhang, Jian,Li, Kexue,Hao, Xiaolin,Labelle, Marc,Smith, Marie-Louise,Rubenstein, Steven M.,Ye, Guosen,McMinn, Dustin,Jackson, Simon,Choi, Rebekah,Shan, Bei,Ma, Ji,Miao, Shichang,Matsui, Takuya,Ogawa, Nobuya,Suzuki, Masahiro,Kobayashi, Akio,Ozeki, Hidekazu,Okuma, Chihiro,Ishii, Yukihito,Tomimoto, Daisuke,Furakawa, Noboru,Tanaka, Masahiro,Matsushita, Mutsuyoshi,Takahashi, Mitsuru,Inaba, Takashi,Sagawa, Shoichi,Kayser, Frank
, p. 3464 - 3483 (2014/05/20)
The discovery and optimization of a series of acyl CoA:diacylglycerol acyltransferase 1 (DGAT1) inhibitors based on a pyrimido[4,5-b][1,4]oxazine scaffold is described. The SAR of a moderately potent HTS hit was investigated resulting in the discovery of phenylcyclohexylacetic acid 1, which displayed good DGAT1 inhibitory activity, selectivity, and PK properties. During preclinical toxicity studies a metabolite of 1 was observed that was responsible for elevating the levels of liver enzymes ALT and AST. Subsequently, analogues were synthesized to preclude the formation of the toxic metabolite. This effort resulted in the discovery of spiroindane 42, which displayed significantly improved DGAT1 inhibition compared to 1. Spiroindane 42 was well tolerated in rodents in vivo, demonstrated efficacy in an oral triglyceride uptake study in mice, and had an acceptable safety profile in preclinical toxicity studies.
Phenyl ketone derivatives
-
, (2008/06/13)
Compounds of the formula I, II or III STR1 in which Ar and Ar' are an oxygen-containing aromatic radical, R1 and R2 are a monovalent hydrocarbon radical which is substituted or unsubstituted, or R1 and R2 togeth
Stereoselectivity in the Hydride Reduction of Acyclic Diketones (1,2-, 1,3-, 1,4-, and 1,5-Induction)
Maier, Guenther,Roth, Cornelia,Schmitt, Reinhart K.
, p. 704 - 721 (2007/10/02)
Diketones 2, 5, 9, and 19 as well as hemiketal 22 react with lithium aluminum hydride to give mixtures of d,l- and meso-diols.The stereochemical assignment of the diols can be obtained either by direct comparison with authentic samples (1,2-diols) or by NMR differentiation of diastereotopic groups (1,3- and 1,5-diols) or by stereospecific cyclization to the sila-heterocycles 12 and 13 (1,4-diols).The 1,2- and 1,4-diketones preferably produce meso-diols, whereas 1,3- and 1,5-diketones mostly lead to d,l-isomers.These alternating stereoselectivities can be explained by a stepwise reduction generating complexes of types 24 - 27 which are attacked by excess hydride via a diastereoface differentiating mode.
