1,1-diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (copy2cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. the important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...

9/11 (september) is one of the influential events in the international politics. in fact this event opens a new chapter of transaction in international relation and has been affected great powers policy and international institution in different aspects. nato as the most important security institution in west also affected by these events. these events have been changed nato strategy in deal wi...

0