The synthesis, structure and properties of diazaphospholes: Reagents and ligands for asymmetric synthesis
摘要:
Reaction of C-2 diamines with PCl3 and Et3N in toluene, followed by water or hydrogen sulfide, gave a series of cyclic phosphorous acid diamides (diazaphosphole oxides) and thiophosphorous acid diamides (diazaphosphole sulfides), respectively. Similarly, reaction of diamines with phenyl dichlorophosphine gave phenyl diazaphospholes. The synthesis, properties, and structure of these diazaphospholes are reported. (C) 1998 Elsevier Science Ltd. All rights reserved.
Samarium Diiodide-Promoted Reductive Coupling of Imines
作者:Tsuneo Imamoto、Seijiro Nishimura
DOI:10.1246/cl.1990.1141
日期:1990.7
Aromatic aldimines are reductively coupled to 1,2-diamines by treatment with samarium diiodide. Cross-coupling of aromatic ketimines with ketones to 2-aminoalcohols is also promoted by the same reagent.
Provide that a useful catalyst for homogeneous hydrogenation, particularly a catalyst for homogeneous asymmetric hydrogenation for hydrogenation, particularly asymmetric hydrogenation, which is obtainable with comparative ease and is excellent in economically and workability, and a process for producing a hydrogenated compound of an unsaturated compound, particularly an optically active compound using said catalyst with a high yield and optical purity.
Reductive amination with zinc powder in aqueous media
作者:Giovanni B Giovenzana、Daniela Imperio、Andrea Penoni、Giovanni Palmisano
DOI:10.3762/bjoc.7.125
日期:——
Zincpowder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.
Visible light mediated homo- and heterocoupling of benzyl alcohols and benzyl amines on polycrystalline cadmium sulfide
作者:Tatiana Mitkina、Christoph Stanglmair、Wolfgang Setzer、Michael Gruber、Horst Kisch、Burkhard König
DOI:10.1039/c2ob07053g
日期:——
The oxidative coupling of sp3 hybridized carbon atoms by photocatalysis is a valuable synthetic method as stoichiometric oxidation reagents can be avoided and dihydrogen is the only byproduct of the reaction. Cadmium sulfide, a readily available semiconductor, was used as a visible light heterogeneous photocatalyst for the oxidative coupling of benzyl alcohols and benzyl amines by irradiation with blue light. Depending on the structure of the starting material, good to excellent yields of homocoupling products were obtained as mixtures of diastereomers. Cross-coupling between benzyl alcohols and benzyl amines gave product mixtures, but was selective for the coupling of tetrahydroisoquinolines to nitromethane. The results demonstrate that CdS is a suitable visible light photocatalyst for oxidative bond formation under anaerobic conditions.
Reduction of imines was performed with zinc powder in 5% aq NaOH solutionwithout any organic solvents under mild conditions, and the corresponding amines were obtained in good yields.