Highly Enantioselective Iridium-Catalyzed Hydrogenation of α,β-Unsaturated Esters
作者:Jia-Qi Li、Xu Quan、Pher G. Andersson
DOI:10.1002/chem.201200907
日期:2012.8.20
α,β‐Unsaturated esters have been employed as substrates in iridium‐catalyzed asymmetric hydrogenation. Full conversions and good to excellent enantioselectivities (up to 99 % ee) were obtained for a broad range of substrates with both aromatic‐ and aliphatic substituents on the prochiral carbon. The hydrogenated products are highly useful as building blocks in the synthesis of a variety of natural
The Ir(I) complexes of chiral spiro phosphinoâoxazoline ligands (SpinPhox) have demonstrated good to excellent enantioselectivity in the asymmetric hydrogenation (AH) of a variety of (E)-β,β-disubstituted α,β-unsaturated N-methoxy-N-methylamides, affording the corresponding optically active Weinreb amides with up to 97% ee.
Enantioselectiveepoxidation of β,β-disubstituted enamides with aqueous hydrogen peroxide and a novel manganesecatalyst is described. Epoxidation is stereospecific and proceeds fast under mild conditions. Amides are disclosed as key functional groups to enable high enantioselectivity.
Enantioselective Markovnikov Addition of Carbamates to Allylic Alcohols for the Construction of α-Secondary and α-Tertiary Amines
作者:Ana Bahamonde、Buthainah Al Rifaie、Victor Martín-Heras、Jamie R. Allen、Matthew S. Sigman
DOI:10.1021/jacs.9b03438
日期:2019.6.5
Herein we describe the development of a Pd-catalyzed enantioselective Markovnikov addition of carbamates to allylic alcohols for the construction of α-tertiary and α-secondary amines. The reaction affords a range of β-amino alcohols, after reduction of the aldehyde in situ, which contain a variety of functional groups in moderate yields and moderate to good enantioselectivities. These products can
Nickel-catalyzed asymmetric transfer hydrogenation of conjugated olefins
作者:Siyu Guo、Peng Yang、Jianrong (Steve) Zhou
DOI:10.1039/c5cc01632k
日期:——
Asymmetrictransferhydrogenation of electron-deficient olefins is realized with nickel catalysts supported by strongly [sigma]-donating bisphosphines. Deuterium labeling experiments points to a reaction sequence of formate decarboxylation, asymmetric hydride insertion...