Modified Sonogashira Reaction Involving Synthetic Control Through Silylacetylene Protecting Group

Dierker, Theresa M., Ariel M. Katsimpalis, Matthew R. Lining, Ciara J. Viola, Jenna L. Wonsowicz, and Matthew J. Mio

Repetitive silylacetylene protection/deprotection is common in the generation of sequence-specific oligo(arylethynylene)s. Modified Sonogashira coupling reactions have been developed that allow for synthetic control of reactive site based on the steric bulk of the terminal acetylene protecting group. Utilization of an amidine base such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), the presence of substoichiometric amounts of water, in addition to Pd catalyst, CuI and organic solvent allow these transformations to proceed with reasonable yield. An orthogonal approach to the generation of these oligomers can allow for rapid molecular prototyping, and in turn, increases the accessibility of high value-added arylethynyl structures.