Enantiomerically Enriched α-Borylzinc Reagents by Nickel-Catalyzed Carbozincation of Vinylboronic Esters
作者:Chenlong Zhang、Weipeng Hu、Gabriel J. Lovinger、Jing Jin、Jingjia Chen、James P. Morken
DOI:10.1021/jacs.1c05274
日期:2021.9.8
In this paper is described a synthesis of enantiomerically enriched, configurationally stable organozinc reagents by catalyticenantioselective carbozincation of a vinylboronic ester. This process furnishes enantiomerically enriched α-borylzinc intermediates that are shown to undergo stereospecific reactions, producing enantioenriched secondary boronic ester products. The properties of the intermediate
Bis-hydroxybenzyl derivatives, processes for their preparation and pharmaceutical composition containing same
申请人:AKZO N.V.
公开号:EP0038600A1
公开(公告)日:1981-10-28
The invention relates to compounds of the formula's:
and salts thereof, in which R, and R2 may be the same or different groups selected from hydroxy, and etherified hydroxy and an esterified hydroxy group, having valuable anti-inflammatory, lipid lowering activities, and immunomodulating properties.
本发明涉及式的化合物:
及其盐类,其中 R 和 R2 可以是相同或不同的基团,选自羟基、醚化羟基和酯化羟基,具有重要的抗炎、降脂活性和免疫调节特性。
Neelima; Bhaduri, A. P., Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1984, vol. 23, # 3, p. 209 - 215
作者:Neelima、Bhaduri, A. P.
DOI:——
日期:——
Intramolecular Regioselective Insertion into Unactivated Prochiral Carbon−Hydrogen Bonds with Diazoacetates of Primary Alcohols Catalyzed by Chiral Dirhodium(II) Carboxamidates. Highly Enantioselective Total Synthesis of Natural Lignan Lactones
作者:Jeffrey W. Bode、Michael P. Doyle、Marina N. Protopopova、Qi-Lin Zhou
DOI:10.1021/jo961607u
日期:1996.1.1
Intramolecular insertion into unactivated prochiral C-H bonds of 3-aryl-1-propyl diazoacetates catalyzed by dirhodium(II) tetrakis[methyl 1-(3-phenyl propanoyl)imidazolidin-2-one-4(R or S)-carboxylate], Rh-2(4R-MPPIM)(4) or Rh-2(4S-MPPIM)(4), occurs in 91-96% ee and with virtually complete regiocontrol for the formation of beta-benzyl-gamma-butyrolactones. This methodology has been applied to the total synthesis of dibenzylbutyrolactone lignans (-)- and (+)-enterolactone, (-)- and (+)-hinokinin, and (+)-arctigenin from substituted cinnamic acids in 19-27% overall yields. Aryltetralin lignan (+)-isodeoxypodophyllotoxin was prepared from the reactant 3,4-(methylenedioxy)cinnamic acid in 36% yield overall, and the lactone precursor to (+)-isolauricerisinol was formed in 96.5% ee and 23% yield overall. Applications of the chiral Rh-2(MPPIM)4 catalysts to fully aliphatic systems resulting in the formation of beta-substituted-gamma-butyrolactones with high regiocontrol and with 93-96% ee have demonstrated the generality of this methodology. A model that provides accurate predictions of beta-substituted-gamma-butyrolactone absolute configurations in these asymmetric metal carbene transformations is described.