Low-temperature ketene formation in materials chemistry through molecular engineering

Leibfarth, F.A.; Wolffs, M.; Campos, L.M.; Delany, K.; Treat, N.; Kade, M.J.; Moon, B.; Hawker, C.J.
, Chem. Sci.,
2012
, 3, 766-771.

The thermolysis of Meldrum's acid derivatives has emerged as a powerful methodology to generate ketenes in polymeric structures, but the required high temperatures for ketene formation may reduce its broad applicability. We take a molecular approach toward addressing this limitation by engineering Meldrum's acid derivatives to undergo thermolysis at significantly lower temperatures. Two distinct strategies are presented and a thorough understanding of the molecular interactions governing their reactivity is provided through model compound design and synthesis, crystal structure analysis, and computation of transition structures. The generality of these molecular design principles allows for the generation of ketenes under mild thermal conditions, providing significant opportunities as a comprehensive and wide-ranging tool for controlling reactivity in both chemical and materials science applications.