simple and efficient procedure for the preparation of silica‐bonded propyl‐diethylene‐triamine‐N‐sulfamic acid (SPDTSA) by reaction of 3‐diethylenetriamine‐propylsilica (DTPS) and chlorosulfonic acid in chloroform is described. Silica‐bonded propyl‐diethylene‐triamine‐N‐sulfamic acid is employed as a recyclable catalyst for the synthesis of 1,1‐diacetates from aromatic aldehydes and acetic anhydride under
Nickel boride mediated chemoselective deprotection of 1,1-diacetates to aldehydes and deprotection with concomitant reduction to alcohols at ambient temperature
作者:Gaurav Bartwal、Mohit Saroha、Jitender M. Khurana
DOI:10.1080/00397911.2017.1390687
日期:2018.1.2
aldehydes as well as deprotected and concomitantly reduced to the corresponding alcohols in high yields at ambient temperature with nickel boride generated in situ using different molar ratios of sodium borohydride and nickel (II) chloride in methanol at room temperature. Deprotection and reduction of a variety of aromatic, aliphatic and heterocyclic acylals have been achieved efficiently. Mild reaction conditions
Reinvestigation of the Mechanism ofgem-Diacylation: Chemoselective Conversion of Aldehydes to Variousgem-Diacylates and Their Cleavage under Acidic and Basic Conditions
作者:Veerababurao Kavala、Bhisma�K. Patel
DOI:10.1002/ejoc.200400584
日期:2005.1
aromatic aldehydes were obtained directly from the reaction of a variety of aliphatic and aromatic acid anhydrides in the presence of a catalytic quantity of tetrabutylammonium tribromide (TBATB) under solvent-free conditions. A significant electronic effect was observed during its formation as well as deprotection to the corresponding aldehyde. Chemoselective gem-diacylation of the aromatic aldehyde containing
Chemoselective Synthesis of 1,1-Diacetates from Aldehydes Using Anhydrous Cobalt(II) Bromide Under Solvent-Free Conditions
作者:Gangadhar A. Meshram、Vishvanath D. Patil
DOI:10.1080/00397910902985499
日期:2010.1.14
mild and efficient method has been developed for the chemoselective preparation of 1,1-diacetates (acylals) from aldehydes catalyzed in the presence of a catalytic amount (0.1 mmol) of anhydrous cobalt(II) bromide under solvent-free conditions. The remarkable selectivity under mild and neutral conditions, excellent yields, short reaction time, and easily available and inexpensive catalyst are important
已开发出一种温和有效的方法,用于在无溶剂条件下,在催化量 (0.1 mmol) 无水溴化钴 (II) 存在下催化醛类化学选择性制备 1,1-二乙酸酯(酰基)。在温和和中性条件下显着的选择性、优异的收率、反应时间短以及易于获得且廉价的催化剂是该方法的重要特征。
Tungstosulfonic acid as an efficient solid acid catalyst for acylal synthesis for the protection of the aldehydic carbonyl group
作者:Reddi Mohan Naidu Kalla、Mi Ri Kim、Yu Na Kim、Il Kim
DOI:10.1039/c5nj02697k
日期:——
Tungstosulfonic acid (TSA) has been found to be an efficient solid acid catalyst for the protection of aldehydic carbonyl groups by geminal diacetate (acylal) formation following the nucleophilic addition of acetic anhydride under neat conditions as well as in a solvent. The TSA catalyst is fully characterized by infrared spectroscopy, wide-angle X-ray scattering analysis, and scanning electron microscopy