摘要
Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated(S)-N-tert-butanesulfinyl ketimines by using Ti(O^iPr)_4 as catalyst and THF as solvent afforded N-tert-butanesulfinamides in good to excellent yields(51-93%) and good diastereoselectivities(dr.85:15 to 93:7).The N-tert -butanesulfinyl group can be readily cleaved under mild acidic condition(4 mol/L HCl in dioxane) to provide the correspondingα-difiuoromethylα-propargylamine in excellent yields(90-95%).
Stereoselective approach for preparation ofα-difluoromethylα-propargylamines has been developed.1,2-Addition of lithium acetylides to diverse chiral difluoromethylated(S)-N-tert-butanesulfinyl ketimines by using Ti(O^iPr)_4 as catalyst and THF as solvent afforded N-tert-butanesulfinamides in good to excellent yields(51-93%) and good diastereoselectivities(dr.85:15 to 93:7).The N-tert -butanesulfinyl group can be readily cleaved under mild acidic condition(4 mol/L HCl in dioxane) to provide the correspondingα-difiuoromethylα-propargylamine in excellent yields(90-95%).
基金
The Shanghai Pujiang Program(No09PJ1400800)
the Fundamental Research Funds for the Central Universities and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry