Catalyst-Free Synthesis of Polysubstituted 5-Acylamino-1,3-Thiazoles via Hantzsch Cyclization of α-Chloroglycinates.

A catalyst-free heterocyclization reaction of α-chloroglycinates with thiobenzamides or thioureas leading to 2,4-disubstituted-5-acylamino-1,3-thiazoles has been developed. The methodology provides straightforward access to valuable building blocks for pharmaceutically relevant compounds.

Synthesis of PEG-Functionalized Amines Using Ruthenium-Catalyzed Hydrogen Borrowing.

The polyethylene glycol (PEG) moiety has become increasingly important in medicinal chemistry. Herein, we describe the PEG functionalization of amines via hydrogen borrowing reductive amination. This was accomplished using the [Ru(p-cymene)Cl2]2 catalyst and phosphorus-containing ligand dppf or DPE to yield a variety of PEGylated primary and secondary amine products. Furthermore, we illustrate the utility of this method with the synthesis of quetiapine (Seroquel) in 62% isolated yield.