Copper complexes of phosphoramidites efficiently catalyzed asymmetricaddition of arylboron reagents to acyclic enones. Importantly, rare 1,4-insertion of arylcopper(I) was identified which led directly to O-bound copper enolates. The new mechanism is fundamentally different from classical oxidative addition/reductive elimination of organocopper(I) on enones.
亚磷酰胺的铜配合物有效地催化芳基硼试剂向无环烯酮的不对称加成。重要的是,鉴定了稀有的芳基铜(I)的 1,4-插入,这直接导致了与 O 结合的铜烯醇化物。新机制与传统的有机铜(I)在烯酮上的氧化加成/还原消除有着根本的不同。
Tandem Addition β-Lithiation−Alkylation Sequence on α,β-Unsaturated Aldehydes
作者:Norma Sbarbati Nudelman、Graciela V. García
DOI:10.1021/jo005698d
日期:2001.2.1
isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that beta-alkyl-substituted alpha,beta-unsaturated aldehydes and aliphatic lithium reagents did not afford good yields of the tandem reaction products, while aromatic lithium reagents gave good results. The aggregation features of the aryllithium
efficient alkylation of β-chloro ketones and their derivatives was achieved by means of domino dehydrochlorination/Mn-enabled radical-based alkyl-alkyl cross-coupling reaction. In situ-generated α,β-unsaturated ketones and their analogues were identified as the reaction intermediates. Known bioactive compounds, such as melperone and azaperone, could be easily prepared from β-chloropropiophenone in two
The addition of Grignardreagents to ketones is significantly enhanced by cerium chloride with remarkable suppression of side reactions, particularly enolization. Some esters, which are prone to side reactions, also react readily with Grignardreagents in the presence of cerium chloride to give normal reaction products in reasonable to high yields.
Pd-Catalyzed Asymmetric Hydrogenation of C=C Bond of α,β-Unsaturated Ketones
作者:Yong-Gui Zhou、Duo-Sheng Wang、Da-Wei Wang
DOI:10.1055/s-0030-1259725
日期:2011.4
Homogenous palladium-catalyzed asymmetric hydrogenation of C=C double bond of alpha,beta-unsaturated ketones has been developed by using palladium(II) trifluoroacetate/(S)-7,7'-bis[ di(4-methoxyphenyl]phosphino)-1,1'-spirobiindane complex [Pd(OCOCF(3))(2)-(S)-An-SDP] as the catalyst under ambient hydrogen pressure and room temperature with up to 89% ee.
使用钯 (II) 三氟乙酸酯/(S)-7,7'-双[二(4-甲氧基苯基]膦基)-开发了均相钯催化的α,β-不饱和酮的C=C双键不对称氢化1,1'-spirobiindane 络合物 [Pd(OCOCF(3))(2)-(S)-An-SDP] 作为催化剂,在环境氢气压力和室温下具有高达 89% 的 ee。