A new series of potent TG2 inhibitors are reported that employ a 4-aminopiperidine core bearing an acrylamide warhead. We establish the structure鈥揳ctivity relationship of this new series and report on the transglutaminase selectivity and in vitro ADME properties of selected compounds. We demonstrate that the compounds do not conjugate glutathione in an in vitro setting and have superior plasma stability over our previous series.