An Efficient Method for Chemoselective Thioacetalization of Aldehydes in the Presence of a Catalytic Amount of Acidic Ionic Liquid under Solvent-Free Conditions
作者:Abdol Hajipour、Ghobad Azizi、Arnold Ruoho
DOI:10.1055/s-0029-1217550
日期:2009.7
A water-stable Brønsted acidic ionic liquid with an alkane sulfonic acid group was synthesized. This ionic liquid catalyzed the thioacetalization reaction smoothly to afford 1,3-dithianes in excellent yield and less time. In this article we describe a mild and chemoselective thioacetalization procedure for the protection of various aldehydes in the presence of catalytic amount of ionic liquid (2 mol%).
Chemoselective thioacetalisation and transthioacetalisation of carbonyl compounds catalysed by tetrabutylammonium tribromide (TBATB)Dedicated to Professor Subramanian Ranganathan on the occasion of his 70th birthday.
作者:Sarala Naik、Rangam Gopinath、Mousumi Goswami、Bhisma K. Patel
DOI:10.1039/b402648a
日期:——
Thioacetals and thioketals of various aldehydes and ketones were obtained directly from carbonylcompounds or by a transthioacetalisation process from cyclic O,O-acetals in the presence of dithiols and a catalytic amount of tetrabutylammonium tribromide (TBATB). Chemoselective thioacetalisation of aromatic aldehydes containing an electron-donating group in the presence of an aldehyde containing an
(1–50 mol %) under ambient conditions to regenerate the original carbonyl compounds in good to excellent yield. This mild, simple, and environmentally benign system is successfully applied to the deprotection of S,O- and O,O-acetals and is compatible with various functional groups. From the mechanistic study of the reaction, the catalytic cycle is considered to be composed of the following four steps: (1) the
An atom-economical diastereoselective synthesis of indenodithiepines and indenodithiocines has been developed via a domino reaction of propargylicalcohols and dithioacetals in the presence of InCl3 as a catalyst. A range of functionalized dithiepines and dithiocines, fused to the indene ring, were obtained in good to excellent yields under mild conditions.
An unprecedented oxidative cross-esterification in an equimolar mixture of dithiolanes, alcohols and water through a CDC/deprotection sequence has been developed. The reaction itself features simple experimental procedures under very mild conditions and offers a new strategic protocol for the direct and efficient synthesis of structurally diverse esters.