Highly regio and chemoselective ring opening of epoxides with trimethylsilyl azide in the presence of aluminium isopropoxide and titanium isopropoxide
摘要:
The ring-opening of functionalized epoxides with trimethylsilyl azide in the presence of a catalytic amount of Ti(O-i-Pr)4 or Al(O-i-Pr)3 is described. The reaction is stereospecific and highly regiospecific, leading generally to the formation of the carbon-azido bond on the less substituted carbon. The mechanism of this reaction is also discussed.
Al(OTf)3 as a highly efficient catalyst for the rapid acetylation of alcohols, phenols and thiophenols under solvent-free conditions
作者:Ahmed Kamal、M. Naseer A. Khan、K. Srinivasa Reddy、Y.V.V. Srikanth、T. Krishnaji
DOI:10.1016/j.tetlet.2007.03.162
日期:2007.5
Aluminium triflate (0.01–0.1 mol %) was found to be an efficientcatalyst for the acylation of alcohols, phenols, thiols and sugars with acetic anhydride in high yields undersolvent-freeconditions in a short reaction time at room temperature. Racemization of optically active alcohols and epimerization of sugars were not observed. The acylation efficacy of various acyl donors was also investigated