نتایج جستجو برای: asymmetric catalyst

تعداد نتایج: 108514  

Journal: :Chemical communications 2013
Takahiro Nishimura Yusuke Ebe Hiroto Fujimoto Tamio Hayashi

Asymmetric addition of arylboronates to aryl-substituted cyclic ketimines proceeded in the presence of a rhodium catalyst coordinated with a chiral diene ligand to give high yields of sulfamidates and sulfamides with high enantioselectivity (up to 99% ee).

Journal: :Organic & biomolecular chemistry 2014
Cunxiang Su Ying Xie Hongjie Pan Mao Liu Hua Tian Yian Shi

This paper describes an efficient asymmetric biomimetic transamination of α-keto esters with a quinine-derived chiral base as the catalyst, giving a variety of β-branched α-amino esters in 50-96% yield and 87-95% ee.

Journal: :Organic letters 2005
You-Qing Wang Sheng-Mei Lu Yong-Gui Zhou

[reaction: see text]. A novel catalytic system for asymmetric hydrogenation of functionalized ketones has been developed using a Pd/bisphosphine complex as the catalyst in 2,2,2-trifluoroethanol. The reaction exhibits high enantioselectivity, and up to 92.2% ee was obtained.

2016
R. N. Straker Q. Peng A. Mekareeya R. S. Paton E. A. Anderson

Transition metals can catalyse the stereoselective synthesis of cyclic organic molecules in a highly atom-efficient process called cycloisomerization. Many diastereoselective (substrate stereocontrol), and enantioselective (catalyst stereocontrol) cycloisomerizations have been developed. However, asymmetric cycloisomerizations where a chiral catalyst specifies the stereochemical outcome of the ...

Journal: :Chemical communications 2010
Jonathan Hopewell Piotr Jankowski Claire L McMullin A Guy Orpen Paul G Pringle

An efficient, classical resolution of the versatile P-ligand intermediate 6-phospha-2,4,8-trioxa-adamantane (CgPH) is described and the rhodium complex of the optically pure secondary phosphine beta-CgPH is an active and moderately selective asymmetric hydrogenation catalyst.

Journal: :Chemical communications 2015
Ziqing Zuo Lei Zhang Xuebing Leng Zheng Huang

A series of iron complexes of chiral iminopyridine-oxazoline (IPO) ligands have been synthesized. The most sterically hindered iron catalyst exhibits excellent activity (up to 99% yield) and high enantioselectivity (up to 93% ee) in asymmetric hydrosilylation of aryl ketones.

Journal: :Chemical communications 2010
Marcus Frings Daniel Goedert Carsten Bolm

Amides with quaternary stereogenic centers have been synthesised by catalytic asymmetric vinylogous Mukaiyama aldol reactions. The chiral copper-sulfoximine catalyst gives rise to products with moderate to good yields and up to 92% ee.

Journal: :Chemical communications 2012
Eun-Young Jeong Cheang-Rae Lim Hailian Jin Sang-Eon Park

trans-1,2-Diaminocyclohexane functionalized mesoporous silica was applied as an ideal catalyst for asymmetric Michael addition of various nitroalkane derivatives. Short channels and plugs in the pore structure offered chiral enhancement in Michael addition.

Journal: :Chemical communications 2006
Sébastien L X Martina Richard B C Jagt Johannes G de Vries Ben L Feringa Adriaan J Minnaard

The catalytic asymmetric 1,2-addition of a series of arylboronic acids to 2,2,2-trifluoroacetophenones is described with high isolated yields (up to 96%) and good enantioselectivities (up to 83% ee) using a rhodium(I)/phosphoramidite catalyst.

Journal: :Organic & biomolecular chemistry 2009
François-Moana Gautier Simon Jones Stephen J Martin

Organocatalysts for the asymmetric reduction of ketimines are presented that function well at low catalyst loadings providing chiral amines in good yield and enantioselectivity, the latter appearing to be independent of the ketimine substrate geometry.

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