α-Methoxyphenyl acetic acid (MPA) for the configurational assignment of aromatic–heteroaromatic carbinols by 1H NMR spectroscopy
摘要:
Configurational assignment for a wide array of arom atic-hetero aromatic carbinols using NMR method employing a-methoxyphenyl acetic acid (MPA) as a convenient and reliable anisotropic agent is described. (c) 2005 Elsevier Ltd. All rights reserved.
This work disclosed a highly enantioselective hydrogenation of non-ortho-substituted 2-pyridyl arylketones via Ir/f-diaphos catalysis. This catalytic system allows for full control over the configuration of the stereocenter, affording two enantiomers of the desired products with extremely high enantioselectivity (up to >99% ee in most cases) and excellent reactivity (TON of up to 19600, TOF of 1633
Highly Enantioselective Hydrogenation of Aromatic-Heteroaromatic Ketones
作者:Cheng-yi Chen、Robert A. Reamer、Jennifer R. Chilenski、Chris J. McWilliams
DOI:10.1021/ol0360795
日期:2003.12.1
Asymmetric hydrogenation of ketone 1 using trans-RuCl(2)[(R)-xylbinap][(R)-daipen] (3) as a catalyst afforded secondary alcohol 2 quantitatively and in 99.4% ee. Further exploration of the effect of the thiazole ring substitution revealed that the catalyst was highly effective for the enantioselectivehydrogenation of 5-benzoyl thiazoles, which afforded corresponding alcohols in 92-99% ee. The same
Preparation of pyridinyl aryl methanol derivatives by enantioselective hydrogenation of ketones using chiral Ru(diphosphine)(diamine) complexes. Attribution of their absolute configuration by 1H NMR spectroscopy using Mosher's reagent
provide highly efficient catalysts for enantioselectivehydrogenation of a series of pyridinyl aryl ketones. The hydrogenation proceeds under mild conditions providing chiral pyridinyl aryl methanol derivatives with consistently high yields and moderate to excellent enantioselectivities (up to 99% ee) according to the structure of the chiral diphosphine. NMR studies, based on Mosher's ester derivatisation
Amino alcohol-boron-binol complex and method for preparing optically active amino alcohol derivative by using same
申请人:MOLECULES & MATERIALS CO., LTD.
公开号:US11130734B2
公开(公告)日:2021-09-28
Disclosed are an amino alcohol-boron-binol complex as an intermediate, including Complex 3-1-1 shown below, and a method for preparing an optically active amino alcohol by using the same, wherein a racemic amino alcohol is resolved in an enationselective manner using a boron compound and a (R)- or (S)-binol, whereby an amino alcohol derivative with high optical purity can be prepared at high yield.
Pyridylmagnesiates: generation by bromine–metal exchange and enantioselective addition to aldehydes
作者:Delphine Catel、Olivier Payen、Floris Chevallier、Florence Mongin、Philippe C. Gros
DOI:10.1016/j.tet.2012.03.058
日期:2012.5
Butyl and dibutylmagnesiates incorporating chiral ligands have been prepared and their reactivity studied. The reagents were efficient to promote the clean bromine-magnesium exchange of azinyl bromides at room temperature and subsequent reaction with aldehydes affording pyridylcarbinols. (R,R)-TADDOL-based dibutylmagnesiate was the best reagent leading to acceptable to good enantioselectivities, depending on the substrate and on the aldehyde substitution. This is the first example of enantioselective addition of in situ generated pyridylmagnesiate to carbonyl electrophiles. (C) 2012 Elsevier Ltd. All rights reserved.