Nucleophilic Substitution Reactions of (Alkoxymethylene)dimethylammonium Chloride
作者:Anthony G. M. Barrett、D. Christopher Braddock、Rachel A. James、Nobuyuki Koike、Panayiotis A. Procopiou
DOI:10.1021/jo980583j
日期:1998.9.1
The use of imidate esters as potential replacements for diethyl azodicarboxylate and triphenylphosphine in the Mitsunobu reaction is described. A series of secondary alcohols were allowed to react with (chloromethylene)dimethylammonium chloride, generated from dimethylformamide (DMF) and oxalyl chloride, to give imidate esters. Reaction of these salts with potassium benzoate or potassium phthalimide
Development of a robust immobilized organocatalyst for the redox-neutral mitsunobu reaction
作者:Leijie Zhou、Stefania Perulli、Marco M. Mastandrea、Patricia Llanes、Junshan Lai、Miquel A. Pericàs
DOI:10.1039/d1gc02819g
日期:——
polystyrene-supported version of the Denton catalyst for redox-neutral Mitsunobureactions, (2-hydroxybenzyl)diphenylphosphine oxide, has been developed and used in catalytic inversion of enantiopure secondary alcohols (21 examples, up to 97% yield and 98% ee) with 2-nitrobenzoic and 2,4-dinitrobenzoic acids. The use in the reaction of alternative pronucleophiles has also been explored (8 successful and
Di-2-methoxyethyl azodicarboxylate (DMEAD) is prepared in 65% yield in two steps as a crystalline solid. Use of DMEAD in the Mitsunobureaction of a variety of alcohols with pronucleophiles results in good yields of the products under sufficient stereospecificity of inversion, as conventional diisopropyl azodicarboxylate (DIAD) does. Isolation of the product is, however, much easier with DMEAD than
2-Arylazocarboxylate and 2-arylazocarboxamide derivatives can serve as replacements of typical Mitsunobu reagents such as diethylazodicarboxylate. A systematic investigation of the reactivity and physical properties of those azo compounds has revealed that they have an excellent ability as Mitsunobu reagents. These reagents show similar or superior reactivity as compared to the known azo reagents