Highly Practical Aqueous Phase Acylation of Phenols, Amines and Alcohols Employing New Green Acylation Reagents Derived From DBU

Abstract Two new Lewis base adducts (LBAs) of DBU were prepared, isolated in grams scale and are employed as Green reagents for base free benzoylation and pivaloylation in water. The structures of these reagents are unambiguously confirmed and the practicality of these LBAs (transient species) in organic synthesis as operationally simple protecting reagents of various phenols, amines, and alcohols in water at ambient temperature is explored. The products are furnished in very good yields (up to 95 %) and are purified just by filtration followed by recrystallization thus avoiding column chromatography. The Lewis base, DBU is recycled and reused for the preparation of LBAs. The methodology is an environmentally benign due to aqueous phase, base free reaction, chromatography free purificatios, ambient temperature reactions and recycling DBU.