- Asymmetric Alkoxy- and Hydroxy-Carbonylations of Functionalized Alkenes Assisted by β-Carbonyl Groups
-
As a fundamental type of carbonylation reaction, the alkoxy- and hydroxy-carbonylation of unsaturated hydrocarbons constitutes one of the most important industrial applications of homogeneous catalysis. However, owing to the difficulties in controlling multi-selectivities for asymmetric hydrocarbonylation of alkenes, this reaction is typically limited to vinylarenes and analogues. In this work, a highly efficient asymmetric alkoxy- and hydroxy-carbonylation of β-carbonyl functionalized alkenes was developed, providing practical and easy access to various densely functionalized chiral molecules with high optical purity from broadly available alkenes, CO, and nucleophiles (>90 examples, 84–99 % ee). This protocol features mild reaction conditions and a broad substrate scope, and the products can be readily transformed into a diverse array of chiral heterocycles. Control experiments revealed the key role of the β-carbonyl group in determining the enantioselectivity and promoting the activity, which facilitates chiral induction by coordination to the transition metal as rationalized by DFT calculations. The strategy of utilizing an innate functional group as the directing group on the alkene substrate might find further applications in catalytic asymmetric hydrocarbonylation reactions.
- Dong, Kaiwu,Ji, Xiaolei,Ren, Xinyi,Shen, Chaoren,Tang, Lin,Tian, Xinxin,Wang, Zhen
-
supporting information
p. 17693 - 17700
(2021/07/10)
-
- Modular 1,1′-Ferrocenediyl-cored P-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
-
A novel ferrocene-based P-stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β-unsubstituted or -substituted itaconates and α-methylene-γ-oxo-carboxylates. (Figure presented.).
- Poklukar, Ga?per,Stephan, Michel,Mohar, Barbara
-
supporting information
p. 2566 - 2570
(2018/05/16)
-
- Enzyme-Inspired Chiral Secondary-Phosphine-Oxide Ligand with Dual Noncovalent Interactions for Asymmetric Hydrogenation
-
Inspired by the unique character of enzymes, we developed novel chiral SPO (secondary-phosphine-oxide) ligand (SPO-Wudaphos) which can enter into both ion pair and H-bond noncovalent interactions. The novel chiral SPO-Wudaphos exhibited excellent results
- Chen, Caiyou,Zhang, Zhefan,Jin, Shicheng,Fan, Xiangru,Geng, Mingyu,Zhou, Yan,Wen, Songwei,Wang, Xinrui,Chung, Lung Wa,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 6808 - 6812
(2017/06/06)
-
- Bicyclic heterocycles as cannabinoid receptor modulators
-
The present application describes compounds according to Formula I, pharmaceutical compositions comprising at least one compound according to Formula I and optionally one or more additional therapeutic agents and methods of treatment using the compounds according to Formula I both alone and in combination with one or more additional therapeutic agents. The compounds have the general Formula I: including all prodrugs, pharmaceutically acceptable salts and stereoisomers, R1, R2, R3, R3a, R4, A, B, n, Y and Z are described herein.
- -
-
Page/Page column 13
(2008/06/13)
-
- Synthesis and hypotensive activity of some 6-(substituted aryl)-4-methyl-2,3-dihydropyridazin-3-ones
-
6-(Substituted aryl)-4-methyl-2,3-dihydropyridazin-3-ones are synthesized by cyclisation of appropriate β-(substituted aroyl)-2-methylene propionate with hydrazine hydrate in the presence of sodium acetate. The title compounds are tested for hypotensive activity, non-invasively, by tail-cuff method and are found to possess significant hypotensive activity in normotensive rats.
- Siddiqui, Anees A.,Wani, Sachin M.
-
p. 1574 - 1579
(2007/10/03)
-
- Compositions containing certain derivatives of 4-phenyl-4-oxobuten-2-oic acid and methods of treatment using them
-
Pharmaceutical compositions including compounds of formula (I): STR1 in which R1 represents a hydrogen atom, a hydroxy radical or an alkyl radical containing from 1 to 8 carbon atoms, R2 represents a hydrogen atom or an alkyl radical containing from 1 to 8 carbon atoms, and R represents a hydrogen atom or an alkyl radical containing from 1 to 8 carbon atoms, as well as the pharmaceutically acceptable alkali metal, alkaline earth metal, ammonium or amine salts of the products of formula I in which R represents a hydrogen atom. These compositions have been found to be useful in treating hyperchlorhydria, gastric and gastroduodenal ulcers, gastritis, hiatal hernias and gastric or gastroduodenal ailments accompanied by gastric hyperacidity.
- -
-
-
- Method of reducing cholesterol using certain aromatic keto acids
-
This invention relates to new chemical compounds useful as drugs, as well as to pharmaceutical compositions containing the same. This application claims their hypocholesterolemic use. The new products are aromatic keto acid compounds with antiinflammatory
- -
-
-