Re2O7-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles
نویسندگان
چکیده
Re(VII) oxides catalyze the acetalization, monoperoxyacetalization, monothioacetalization and allylation of hemiacetals. The reactions, which take place under mild conditions and at low catalyst loadings, can be conducted using hemiacetals, the corresponding O-silyl ethers, and, in some cases, the acetal dimers. Aldehydes react under similar conditions to furnish good yields of dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or a Brønsted acid.
منابع مشابه
(Diacetoxyiodo)benzene (DIB) catalyzed green and efficient synthesis of biscoumarin derivatives in aqueous media
(Diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. This aqua mediated Knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...
متن کاملBaker’s yeast catalyzed Henry reaction: Biocatalytic C-C bond formation
The C-C bond formation is an important reaction in organic synthesis to obtain value-added intermediates. Therefore, in this paper an attempt has been made to accelerate the Henry reaction (C-C bond formation) between aryl aldehydes and nitromethane using less expensive whole cell biocatalyst, baker’s yeast (BY). The scope of the methodology was also tested for the heteryl aldehyde i.e. 2-chlor...
متن کاملAn efficient and one-pot green synthesis of 2-arylsubstituted benzimidazoles catalyzed by nano-Fe3O4@silica sulfuric acid as a recyclable nanomagnetic solid acid catalyst
An efficient and green protocol for the synthesis of 2-arylsubstituted benzimidazoles via a condensation reaction of aromatic aldehydes and 1,2-phenylenediamine using nano-Fe3O4@SiO2-SO3H as a solid acid catalyst in ethanol under reflux conditions has been described. The reactions are completed in short times, and the corresponding benzimidaz...
متن کامل(Diacetoxyiodo)benzene (DIB) catalyzed green and efficient synthesis of biscoumarin derivatives in aqueous media
(Diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. This aqua mediated Knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...
متن کاملThe green synthesis of pyrano[3,2-c]quinoline-2,5-dione derivatives catalyzed by acidic ionic liquid under ultrasound irradiation
Abstract-A novel and efficient method has been developed for the synthesis of pyrano[3,2-c]quinoline-2,5-dione derivatives by the convenient ultrasound-mediated condensation of 4-hydroxyquinolin-2-one with Meldrum’s acid and aldehydes in the presence of a catalytic amount of [HMIm]HSO4 as a green, efficient and reusable acidic ionic liquid medium. The stability of the ionic liquid during the re...
متن کامل