1357183-72-2Relevant academic research and scientific papers
Application of bidentate oxazoline-carbene ligands with planar and central chirality in asymmetric β-Boration of α,β-unsaturated esters
Niu, Zonghong,Chen, Jianqiang,Chen, Zhen,Ma, Manyuan,Song, Chun,Ma, Yudao
, p. 602 - 608 (2016/09/09)
A series of new oxazoline-substituted imidazolium salts based on [2.2]paracyclophane were synthesized and characterized. The new bidentate oxazoline-carbene precursor with planar and central chirality had significant advantage than the bicyclic 1,2,4-triazolium salt derived from [2.2]paracyclophane as a monodentate carbene ligand in Cu(I)-catalyzed asymmetric β-boration of α,β-unsaturated esters, giving the desired products in high enantioselectivities and yields.
Iron catalyzed asymmetric hydrogenation of ketones
Li, Yanyun,Yu, Shenluan,Wu, Xiaofeng,Xiao, Jianliang,Shen, Weiyi,Dong, Zhenrong,Gao, Jingxing
supporting information, p. 4031 - 4039 (2014/04/03)
Chiral molecules, such as alcohols, are vital for the manufacturing of fine chemicals, pharmaceuticals, agrochemicals, fragrances, and novel materials. These molecules need to be produced in high yield and high optical purity and preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetric hydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes use catalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium and rhodium catalysts. By combining a chiral, 22-membered macrocyclic ligand with the cheap, readily available Fe 3(CO)12, a wide variety of ketones have been hydrogenated under 50 bar H2 at 45-65 C, affording highly valuable chiral alcohols with enantioselectivities approaching or surpassing those obtained with the noble metal catalysts. In contrast to AH by most noble metal catalysts, the iron-catalyzed hydrogenation appears to be heterogeneous.
Asymmetric β-boration of α,β-unsaturated carbonyl compounds with chiral Rh[bis(oxazolinyl)phenyl] catalysts
Toribatake, Kenji,Zhou, Li,Tsuruta, Ayae,Nishiyama, Hisao
, p. 3551 - 3560 (2013/05/08)
Chiral rhodium[bis(oxazolinyl)phenyl] complexes exhibited high catalytic activity for the β-boration of α,β-unsaturated esters, ketones, and amides with bis(pinacolato)diboron in the presence of sodium tert-butoxide to attain high enantioselectivity of up to 97%. The substrate scope and catalytic mechanism were discussed.
Chiral iridium catalysts bearing spiro pyridine-aminophosphine ligands enable highly efficient asymmetric hydrogenation of β-aryl β-ketoesters
Xie, Jian-Hua,Liu, Xiao-Yan,Yang, Xiao-Hui,Xie, Jian-Bo,Wang, Li-Xin,Zhou, Qi-Lin
supporting information; experimental part, p. 201 - 203 (2012/03/10)
Tons of TONs: Chiral iridium catalysts bearing ligand 1 are highly efficient for the asymmetric hydrogenation of β-substituted β-ketoesters. The product β-hydroxyesters are delivered in high yield with excellent enantioselectivities and high turnover numbers (TONs). cod= 1,5-cyclooctadiene.
