Chemoselective deprotection and deprotection with concomitant reduction of 1,3-dioxolanes, acetals and ketals using nickel boride
作者:Jitender M. Khurana、Kiran Dawra、Purnima Sharma
DOI:10.1039/c4ra15404e
日期:——
An efficient and mild methodology for the reductive deprotection of 1,3-dioxolanes, acetals and ketals to the corresponding aldehydes/ketones and also deprotection with concomitant reduction to the corresponding alcohols has been achieved in quantitative yields using nickel boride generated in situ from nickel chloride and sodium borohydride in methanol. The reactions are chemoselective as halo, alkoxy
Synthesis and characterization of a tetracationic acidic organic salt and its application in the synthesis of bis(indolyl)methanes and protection of carbonyl compounds
A new tetracationic acidic organic salt (TCAOS) based on DABCO was prepared, characterized and applied as an eco-friendly, powerful and reusable catalyst for the synthesis of bis(indolyl)methanes from indoles and carbonylcompounds in water with high turnover frequency (TOF). Also, this catalyst was successfully applied for acetalization of carbonylcompounds with diols under solvent-free conditions
Intermolecular Reactions of Chlorohydrine Anions: Acetalization of Carbonyl Compounds under Basic Conditions
作者:Michał Barbasiewicz、Mieczysław Ma̧kosza
DOI:10.1021/ol0613113
日期:2006.8.1
[reaction: see text] Nonenolizable aldehydes and ketones react with 2-chloroethanol and 3-chloropropanol under basic conditions (t-BuOK, DMF/THF) with formation of 2-substituted 1,3-dioxolanes and 1,3-dioxanes, respectively. Conversion of the two-step addition-alkylation process depends on the electrophilicity of the carbonyl group that governs the equilibrium of addition of chloroalkoxides. This method
A simple method for the synthesis of 1,3-dioxolanes from carbonyl compounds has been developed using 1,2-bis(trimethylsilyloxy)ethane in the presence of bismuth(III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap.
Palladium-catalyzed enolate arylation as a key C–C bond-forming reaction for the synthesis of isoquinolines
作者:Ben S. Pilgrim、Alice E. Gatland、Carlos H. A. Esteves、Charlie T. McTernan、Geraint R. Jones、Matthew R. Tatton、Panayiotis A. Procopiou、Timothy J. Donohoe
DOI:10.1039/c5ob02320c
日期:——
those that give rise to the traditionally difficult to access electron-deficient isoquinoline skeletons. These two synthetic operations can be combined to give a three-component, one-pot isoquinoline synthesis. Alternatively, cyclization of the intermediates with hydroxylamine hydrochloride engenders direct access to isoquinoline N-oxides; and cyclization with methylamine, gives isoquinolinium salts. Significant