Umpolung reactions of imines, especially the asymmetric reactions, have been extensively studied as they provide access to important chiral amines in an efficient manner. The reactions studied range from simple Michael reactions to several kinds of other reactions such as the aza-benzoin reaction, aza-Stetter reaction, addition with MBH carbonate, and Ir-catalysed allylation. Herein, we report the
A highlyenantioselectiveFriedel–Craftsalkylation reaction of indoles with acyclic α-substituted β-nitroacrylates is developed under the catalysis of Ni(ClO4)2–bisoxazoline complex at 1 mol % catalyst loading, affording chiral indolic β-nitroesters bearing all-carbon quaternary stereocenters in excellent yields and ees of up to 97%. Transformation of one of the products to β2,2-amino ester and t
Iron‐Catalyzed Cleavage Reaction of Keto Acids with Aliphatic Aldehydes for the Synthesis of Ketones and Ketone Esters
作者:Fangyuan Zhou、Lesong Li、Kao Lin、Feng Zhang、Guo‐Jun Deng、Hang Gong
DOI:10.1002/chem.202000114
日期:2020.4
The radical-radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical-radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphaticaldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained
Amino Acid Salt Catalyzed Asymmetric Synthesis of 1,2-Diols with A Quaternary Carbon Center
作者:Jun Jiang、Quanquan Wu、Shulei Liu、Fangyuan Wang、Qingqing Li、Kangli Cheng、Juan Li
DOI:10.1055/s-0035-1560179
日期:——
which demand for both good diastereo- and enantioselectivity. As part of our continuous effort to explore the unique catalytic activities of amino acid salts in the asymmetric synthesis, herein, we wish to report an amino acidsaltcatalyzed direct aldolreaction between hydroxyacetone and α-keto esters, which afforded the 1,2-diols with a quaternary carbon center in high diastereo- and enantioselectivities
Ir/PTC cooperatively catalyzed asymmetric umpolung allylation of α-imino ester enabled synthesis of α-quaternary amino acid derivatives bearing two vicinal stereocenters
作者:Yong-Liang Su、Yu-Hui Li、Yu-Gen Chen、Zhi-Yong Han
DOI:10.1039/c6cc09654a
日期:——
A novel Ir/PTC cooperatively catalyzed asymmetric umpolung addition of simple [small alpha]-imino esters is developed and it provides facile access to [small alpha]-quaternary amino acidderivatives bearing two vicinal stereocenters. Both the...