【有机】请问下各位大..【有机】请问下各位大佬,Weitz-Scheffer反应的机理是怎样的,谢谢!(α,β-不饱和酮在过氧化氢作用下,双键被环氧化)up
Diastereoselective Weitz-Scheffer epoxidation of levoglucosenone for the synthesis of isolevoglucosenone and derivativesLevoglucosenoneEpoxideDiastereoselectiveHydroperoxideIsolevoglucosenoneHigh-yielding epoxidation conditions for the cellulose pyrolysis product (-)-levoglucosenone (LGO) and 3-aryl derivatives of...
The asymmetric Weitz−Scheffer epoxidation of the isoflavones 3, mediated by the cinchonine- and cinchonidine-derived phase-transfer catalysts (PTCs) 1, affords the enantiomerically enriched isoflavone epoxides 4 with ee values of up to 98% in nearly quantitative yields. With the appropriately configu...
The selectivity observed for the 1,4-addition suggested that these derivatives might also serve as Weitz-Scheffer epoxidation substrates, and could be used to prepare 3-arylisolevoglucosenone derivatives in a concise manner using Banwell's approach [10]. An investigation into this chemistry has ...
Weitz−Scheffer reactionThe enantioselective epoxidation of the α,β-enones 1 with the optically active hydroperoxides ()-( S )- 2 , catalyzed by the bases KOH or DBU, affords the enantiomerically enriched oxo epoxides 3 in high yields and with good enantioselectivities (up to 90% ee for...
epoxidationchiral peroxidestemplate structuresWeitz-Scheffer reactionThe enantioselective epoxidation of the α,β-enones 1 with the optically active hydroperoxides (-)-(S)-2, catalyzed by the bases KOH or DBU, affords the enantiomerically enriched oxo epoxides 3 in high yields and with good enantio...
Colonna S,Gaggero N,Manfredi A, et al.Asymmetric Weitz-Scheffer epoxidation promoted by bovine serum albumin. Part III. Highly stereoselective synthesis of optically active epoxynaphthoquinones. Tetrahedron . 1988Colonna S,Gaggero N,Manfredi A, et al.Asymmetric Weitz-Scheffer epoxidation promoted by ...
Bortolini, O
Examines the asymmetric Weitz--Scheffer epoxidation of isoflavones with hydroperoxides. Enantiomers of the isoflavone epoxides; Mechanisms on the asymmetric oxygen-transfer process; Importance of the phase-transfer catalyst structure.AdamWaldemarRaoParaselli...
The epoxidation of electron-deficient olefins using hydrogen peroxide in a strong alkaline solution and is generally known as the Weitz–Scheffer epoxidation. Occasionally, it is also referred to as the Weitz–Scheffer reaction. The asymmetric Weitz–Scheffer epoxidation has been widely used in organic...