The nucleophilic opening of functionalized azetidinium ions by C-nucleophiles was screened. Malonate and cyanide anions reacted in a highly regio- and chemoselective way leading to functionalized pure amines. The success of this reaction was found to be highly dependent on the basicity of the involved nucleophiles and the competitive reactions induced by too basicreagents were identified.
Chemo- and regioselective reductive opening of azetidinium ions
作者:François Couty、Olivier David、François Durrat
DOI:10.1016/j.tetlet.2006.11.175
日期:2007.2
Enantiomerically pure azetidinium trifluoromethanesulfonates were opened by various hydride reagents. LiAlH4 and NaBH3CN reacted with a complete regioselectivity and the latter reagent also reacted in a chemoselective way, leaving unaffected an ester or a cyano moiety present in the substrate. This reaction provides 1,2-diamines, 1,2- and 1,4-amino alcohols or α-amino esters by combining proper choice
Nucleophilicring-opening reactions of azetidine-2-carboxylic acid-derived ammonium salts with fluoride (F−) to afford α-fluoro-γ-aminobutyric acid (α-fluoro-GABA) derivatives were successfully demonstrated. For example, the nucleophilicring-opening reaction of 1-benzyl-2-(tert-butoxycarbonyl)-1-methylazetidin-1-ium triflate with 1.2 equivalents of tetramethylammonium fluoride (Me4NF) in DMF at room