WebJul 18, 2011 · Abstract. Through the design and synthesis of a new chiral phosphepine, the first catalytic asymmetric method for the [3 + 2] cycloaddition of allenes with olefins has been developed that generates cyclopentenes that bear nitrogen-, phosphorus-, oxygen-, and sulfur-substituted quaternary stereocenters. A wide array of racemic γ-substituted ... WebFrench: ·(organic chemistry) phosphepine ... Definition from Wiktionary, the free dictionary

检索结果-暨南大学图书馆

WebJul 8, 2002 · It is worthwhile mentioning that this chlorophosphepine is an extremely useful building block for the synthesis of a variety of substituted 4,5-dihydro-3H-dinaphtho[2,1-c;1′,2′-e]phosphepine ligands 1 by uncomplicated Grignard reaction. Hence, ligands 1e–g were prepared without optimization in 62–76% yield. It is easily foreseen that ... WebApr 18, 2024 · 17 monodentate phosphepine ligands with a 4,5-dihydro-3H-dinaphtho[2,1-c;1′,2′-e]phosphepine structural motif have been synthesized and tested in the asymmetric … green beret physical requirements

Phosphine-catalyzed asymmetric additions of malonate esters to …

WebLa France pourra-t-elle encore exporter des céréales vers l'Afrique le 25 avril ? Le gouvernement se veut rassurant, alors que producteurs et négociants redoutent de ne … WebOct 10, 2009 · Phosphepine 1 has been reported to serve as a chiral ligand for rhodium-catalyzed hydrogenations and hydroformylations, but to the best of our knowledge it has not previously been employed as a nucleophilic catalyst. 13, 14 Table 1 Catalytic asymmetric γ addition of a carbon nucleophile to an allene: Effect of reaction parameters. WebThrough the design and synthesis of a new chiral phosphepine, the first catalytic asymmetric method for the [3 + 2] cycloaddition of allenes with olefins has been developed that generates cyclopentenes that bear nitrogen-, phosphorus-, oxygen-, and sulfur-substituted quaternary stereocenters. A wide array of racemic γ-substituted allenes can ... green berets definition history