The conversion of alcohols to protected amines, such as acetamides, is an important process in synthetic organic chemistry. While this transformation has several solutions, research in this area continues to develop as rapid, environmentally friendly and economical methods are still highly desirable. The goal of this research was to determine if benzylic trichloroacetimidates, which are easily synthesized from benzylic alcohols and trichloroacetonitrile, could be rearranged to benzylic acetamides, which are easily transformed to their corresponding amines. This transformation is known for allylic trichloroacetimidates but usually proceeds through a [3,3] sigmatropic rearrangement, which is unavailable to most benzylic systems. Attempts to directly convert the benzylic trichloroacetimidates to their corresponding trichloroacetamides are described. In the presence of an acid catalyst the reaction proceeded in synthetically useful yields. A number of Lewis and Brønsted acids were screened, and TMSOTf emerged as the catalyst that gave the best yields. The utility and generality of this approach was tested by applying the method to a number of imidates. Progression of the rearrangement was evident in most systems and wide ranges of trichloroacetamides were formed from their corresponding imidates in good to excellent yield. As a control, attempts were made to rearrange the benzylic trichloroacetimidates under thermal conditions (toluene, reflux) without a catalyst. However, under thermal conditions product was only observed in highly reactive systems. This research may be used as a cost-effective, atom-economical, operationally simple protocol to convert benzylic alcohols to their corresponding amines using readily available commercial reagents. Funder Acknowledgements: I would like to thank the Syracuse NSF/REU program and the Syracuse LSAMP program for funding. Faculty Advisor: John D. Chisholm, jdchisho@syr.edu

Exploring the rearranagement of complex benzylic trichloroacetimidates to benzylic trichloroacetamides

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.