92520-14-4Relevant academic research and scientific papers
Biocatalytic, Intermolecular C?H Bond Functionalization for the Synthesis of Enantioenriched Amides
Arnold, Frances H.,Athavale, Soumitra V.,Gao, Shilong,Hirschi, Jennifer S.,Liu, Zhen,Mallojjala, Sharath Chandra
supporting information, p. 24864 - 24869 (2021/10/15)
Directed evolution of heme proteins has opened access to new-to-nature enzymatic activity that can be harnessed to tackle synthetic challenges. Among these, reactions resulting from active site iron-nitrenoid intermediates present a powerful strategy to forge C?N bonds with high site- and stereoselectivity. Here we report a biocatalytic, intermolecular benzylic C?H amidation reaction operating at mild and scalable conditions. With hydroxamate esters as nitrene precursors, feedstock aromatic compounds can be converted to chiral amides with excellent enantioselectivity (up to >99 % ee) and high yields (up to 87 %). Kinetic and computational analysis of the enzymatic reaction reveals rate-determining nitrenoid formation followed by stepwise hydrogen atom transfer-mediated C?H functionalization.
A Single Lipase-Catalysed One-Pot Protocol Combining Aminolysis Resolution and Aza-Michael Addition: An Easy and Efficient Way to Synthesise β-Amino Acid Esters
Xu, Fan,Wu, Qiongsi,Chen, Xiaoyang,Lin, Xianfu,Wu, Qi
supporting information, p. 5393 - 5401 (2015/08/24)
A novel one-pot protocol combining aza-Michael addition and aminolysis resolution was developed to obtain chiral β-amino acid esters with lipase B from Candida antarctica (CAL-B) as the only catalyst. This method is conducted under mild reaction conditions and is very easy to handle. After a series of detailed optimization studies, ten racemic aromatic or aliphatic amines were subjected to this one-pot procedure, and twelve chiral β-amino acid esters and ten chiral amides were successfully synthesised with excellent ee values in theoretical yields. Scaled-up procedures also worked without apparent reduction in reaction rate or enantioselectivity, which makes this method suitable for large-scale production of chiral β-amino acid esters. A one-pot protocol for simultaneous synthesis of chiral β-amino acid esters and amides was developed by combining single lipase B from Candida antarctica (CAL-B) catalysed aza-Michael addition and aminolysis resolution. This method requires mild reaction conditions and is very easy to handle. Chiral β-amino acid esters and chiral amides were obtained with excellent ee values and in theoretical yields.
One-pot stibine modified Co2(CO)8 catalyzed reductive N-alkylation of primary amides with carbonyl compounds
Rubio-Pérez, Laura,Sharma, Pankaj,Pérez-Flores, F. Javier,Velasco, Luis,Arias, J. Luis.,Cabrera, Armando
experimental part, p. 2342 - 2348 (2012/04/10)
A one-pot stibine modified Co2(CO)8 homogeneous catalytic reductive N-alkylation of primary amides using aldehydes/ketones as alkylating agents, is reported. Good to excellent yields of a wide range of secondary amides are obtained (up to 97%) under relative mild conditions.
THIAZOLE COMPOUNDS USEFUL AS ACETYL-COA CARBOXYLASE (ACC) INHIBITORS
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Page/Page column 54; 55, (2013/03/15)
The present invention provides thiazole compounds of Formula I or its pharmaceutically acceptable salts, prodrugs, solvates, N-oxide thereof; solvates of pharmaceutically acceptable salts and N-oxides; pharmaceutically acceptable salts of N-oxides, or prodrugs; or combination or mixtures thereof; (I) The present invention further provides a method for preventing or treating a condition that responds to an Acetyl-CoA Carboxylase (ACC) inhibitor by using compounds of formula (I) or ), its pharmaceutically acceptable salts, prodrugs, solvates, N-oxide thereof; solvates of pharmaceutically acceptable salts and N-oxides; pharmaceutically acceptable salts of N-oxides, or prodrugs; or combination or mixtures thereof.
Dynamic path bifurcation in the Beckmann reaction: Support from kinetic analyses
Yamamoto, Yutaro,Hasegawa, Hiroto,Yamataka, Hiroshi
experimental part, p. 4652 - 4660 (2011/07/29)
The reactions of oximes to amides, known as the Beckmann rearrangement, may undergo fragmentation to form carbocations + nitriles when the migrating groups have reasonable stability as cations. The reactions of oxime sulfonates of 1-substituted-phenyl-2-propanone derivatives (7-X) and related substrates (8-X, 9a-X) in aqueous CH3CN gave both rearrangement products (amides) and fragmentation products (alcohols), the ratio of which depends on the system; the reactions of 7-X gave amides predominantly, whereas 9a-X yielded alcohols as the major product. The logk-logk plots between the systems gave excellent linear correlations with slopes of near unity. The results support the occurrence of path bifurcation after the rate-determining TS of the Beckmann rearrangement/fragmentation reaction, which has previously been proposed on the basis of molecular dynamics simulations. It was concluded that path-bifurcation phenomenon could be more common than thought and that a reactivity-selectivity argument based on the traditional TS theory may not always be applicable even to a well-known textbook organic reaction.
Electron-donating and rigid p-stereogenic bisphospholane ligands for highly enantioselective rhodium-catalyzed asymmetric hydrogenations
Zhang, Xiaowei,Huang, Kexuan,Hou, Guohua,Cao, Bonan,Zhang, Xumu
supporting information; experimental part, p. 6421 - 6424 (2010/12/19)
More electron donating, more rigid: A new highly electron-donating P-stereogenic bisphospholane ligand (ZhangPhos) was synthesized in a practical and highly enantioselective manner from a commercially available chiral source. Better or comparable enantioselectivities and reactivities than TangPhos were achieved in rhodium-catalyzed hydrogenation of various functionalized olefins (see scheme; nbd=3,5-norbornadiene). Copyright
Highly enantioselective hydrogenation of enamides catalyzed by chiral phosphoric acids
Li, Guilong,Antilla, Jon C.
supporting information; experimental part, p. 1075 - 1078 (2009/07/25)
A highly enantioselective hydrogenation of enamides catalyzed by a dual chiral-achiral acid system was developed. By employing a substoichiometric amount of a chiral phosphoric acid and acetic acid, catalyst loadings as low as 1 mol % of the chiral cataly
Iodine-mediated ring-closing iodoamination with concomitant N-debenzylation for the asymmetric synthesis of polyhydroxylated pyrrolidines
Davies, Stephen G.,Nicholson, Rebecca L.,Price, Paul D.,Roberts, Paul M.,Russell, Angela J.,Savory, Edward D.,Smith, Andrew D.,Thomson, James E.
experimental part, p. 758 - 772 (2009/09/30)
Treatment of a range of homochiral unsaturated β-amino esters (containing a cis-dioxolane unit) with iodine promotes a novel ring-closing alkene iodoamination reaction which proceeds with concomitant N-debenzylation, providing a simple and stereoselective
Axial 4,4′,6,6′-tetrakis-trifluoromethyl-biphenyl-2, 2′diamine (TF-BIPHAM): Resolution and applications in asymmetric hydrogenation
Wang, Chun-Jiang,Gao, Feng,Liang, Gang
supporting information; experimental part, p. 4711 - 4714 (2009/05/31)
(Equation Presented) The racemic TF-BIPHAM was resolved for the first time, and the effectiveness of the resolved diamine was demonstrated by highly enantioselective hydrogenation of α-aryl enamides and α-dehydroamino acid esters using readily accessible
Asymmetric enamide hydrogenation using planar-chiral cyrhetrenes
Stemmler, René T.,Bolm, Carsten
, p. 6189 - 6191 (2008/03/12)
The catalytic asymmetric hydrogenation of α-arylenamides using catalysts prepared in situ from [Rh(cod)2]BF4 and cyrhetrenyldiphosphines was effective with a range of enamides. The corresponding acetamides were obtained with up to 93
