Easily accessible and highly tunable bisphosphine ligands for asymmetric hydroformylation of terminal and internal alkenes
An efficient methodology for synthesizing a small library of easily tunable and sterically bulky ligands for asymmetric hydroformylation (AHF) has been reported. Five groups of alkene substrates have been tested with excellent conversions, moderate-to-excellent regio- and enantioselectivities. Among the best result of the reported literature, application of ligand 1 c in the highly selective AHF of the challenging substrate 2,5-dihydrofuran yielded almost one isomer in up to 99 % conversion along with enantiomeric excesses (ee) of up to 92 %. Highly enantioselective AHF of dihydropyrrole substrates is achieved using the same ligand, with up to 95 % ee and up to >1:50 β-isomer/α- isomer ratio. The simpler the better! An efficient method for the easy and tunable synthesis of a series of asymmetric hydroformylation (AHF) ligands from low-cost, commercially available starting materials has been reported. These ligands can give excellent conversions and moderate to excellent regio- and enantioselectivities for a broad range of mono- and disubstituted alkenes with a low catalyst loading (substrate-to-catalyst ratios (S/C) of 1000:1 to 3000:1).
Xu, Kun,Zheng, Xin,Wang, Zhiyong,Zhang, Xumu
p. 4357 - 4362
(2014/05/06)
Rhodium-catalyzed asymmetric hydroformylation of n-allvlamides: Highly enantioselective approach to β2-amino aldehydes
(Figure Presented) You're having a lahf I The asymmetric hydroformylation (AHF) of allylic compounds, catalyzed by a rhodium-yanphos complex, is a direct and concise route to ss2-amino aldehydes, acids, and alcohols with excellent enantioselectivity (see scheme; TON =turnover number, acac = acetylacetonate).
Zhang, Xiaowei,Cao, Bonan,Yu, Shichao,Zhang, Xumu
supporting information; experimental part
p. 4047 - 4050
(2010/08/07)
Optimization of 1,4-diazepan-2-one containing dipeptidyl peptidase IV inhibitors for the treatment of type 2 diabetes
Following the discovery of N-acyl-1,4-diazepan-2-one as a novel pharmacophore for potent and selective DPP-4 inhibitors, optimization of this new lead with different substitution on the seven-membered ring resulted in several highly potent and selective,
Liang, Gui-Bai,Qian, Xiaoxia,Feng, Dennis,Biftu, Tesfaye,Eiermann, George,He, Huaibing,Leiting, Barbara,Lyons, Kathy,Petrov, Aleksandr,Sinha-Roy, Ranabir,Zhang, Bei,Wu, Joseph,Zhang, Xiaoping,Thornberry, Nancy A.,Weber, Ann E.
p. 1903 - 1907
(2008/02/04)
DIPEPTIDYL PEPTIDASE-IV INHIBITING COMPOUNDS, METHODS OF PREPARING THE SAME, AND PHARMACEUTICAL COMPOSITIONS CONTAINING THE SAME AS AN ACTIVE AGENT
The present invention relates to novel compounds exhibiting good inhibitory activity versus Dipeptidyl Peptidase-IV(DPP-IV), methods of preparing the same and pharmaceutical compositions containing the same as an active agent.
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Page/Page column 128
(2010/11/24)
Highly enantioselective conjugate addition of dialkylzinc reagents to acyclic nitroalkenes: A catalytic route to β2-amino acids, aldehydes, and alcohols
Using chiral phosphoramidite ligand (S,R,R)-L1 in the conjugate addition to acyclic nitroalkenes for the first time, we obtained enantioselectivities up to 98%. The use of acyclic substrates with different dialkylzinc reagents provides a catalytic enantio
Duursma, Ate,Minnaard, Adriaan J.,Feringa, Ben L.
p. 3700 - 3701
(2007/10/03)
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