Synthesis of α-hydroxy-γ-butyrolactones from acrylates and 1,3-dioxolanes using N-hydroxyphthalimide (NHPI) as a key catalyst
摘要:
A new route to alpha-hydroxy-gamma-butyrolactones through three-component radical coupling of 1,3-dioxoranes, acrylates, and molecular oxygen using N-hydroxyphthalimide (NHPI) as a key catalyst has been developed. For example, the addition of 1,3dioxarane to methyl acrylate under dioxygen by NHPI followed by catalytic hydrogenation of the resulting adduct on Pd/C afforded alpha-hydroxy-gamma-butyrolactone in good yield. This method provides a facile approach to alpha-hydroxy-gamma-butyrolactones, which are difficult to synthesize by conventional methods. (c) 2005 Elsevier Ltd. All rights reserved.
N-Hydroxyphthalimide-catalyzed radical addition of 1,3-dioxolanes and molecular oxygen to alkenes under ambient conditions: a new route to β-oxycarbonyl compounds
A novel catalytic hydroxyacylation of alkenes using 1,3-dioxolanes and molecular oxygen has been developed, and the reaction of 2-methyl-1,3-dioxolane with methyl acrylate under dioxygen atmosphere in the presence of catalytic amounts of NHPI and Co(OAc)2 produced the corresponding adduct in 81% yield.
Synthesis of (+)- and (-)-N-BOC-7-Azabicyclo[2.2.1]heptan-2-ones, Versatile Intermediates for the Enantiospecific Synthesis of (+)- and (-)-Epibatidine and Analogs
作者:Andres Hernandez、Manuel Marcos、Henry Rapoport
DOI:10.1021/jo00114a015
日期:1995.5
(+)- and (-)-Epibatidine, nonopiate antinociceptive alkaloids, have been prepared from (-)- and (+)-N-BOC-7-azabicyclo[2.2.1]heptan-2-one which were produced by resolution of the racemic mixture of the corresponding alcohols obtained in the previous racemic synthesis. In the present work, we report the enantiospecific synthesis of(-)- and (+)-N-BOC-7-azabicyclo[2.2.1]heptan-2-one from L-glutamic acid and levulinic acid. Also, this report describes the selective formation of trans-2,3-disubstituted-7-azabicyclo[2.2.1]heptanes from N-benzyl-5-(1'-methoxycarbonyl-3'-oxobutyl)proline via a decarbonylation/iminium ion cyclization process. These functionalized intermediates are of potential value for the enantiospecific synthesis of epibatidine analogues.
A new route to alpha-hydroxy-gamma-butyrolactones through three-component radical coupling of 1,3-dioxoranes, acrylates, and molecular oxygen using N-hydroxyphthalimide (NHPI) as a key catalyst has been developed. For example, the addition of 1,3dioxarane to methyl acrylate under dioxygen by NHPI followed by catalytic hydrogenation of the resulting adduct on Pd/C afforded alpha-hydroxy-gamma-butyrolactone in good yield. This method provides a facile approach to alpha-hydroxy-gamma-butyrolactones, which are difficult to synthesize by conventional methods. (c) 2005 Elsevier Ltd. All rights reserved.
Anthrone-derived NHPI analogues as catalysts in reactions using oxygen as an oxidant
作者:Juan Shen、Choon-Hong Tan
DOI:10.1039/b812351a
日期:——
An enantioselective synthesis of anthrone-derived NHPI analogues has been developed. One of these analogues, in combination with Co salts, was employed to catalyse the aerobic oxidation of benzylic compounds and diols. Exploratory studies using a racemic version of the catalyst were also conducted. Radical addition of dioxolanes or alcohols to activated alkenes with molecular oxygen as the terminal oxidant was also shown to be catalysed with NHPI analogues.