A new selenophosphoramide-catalyzed diamination of terminal- and -1,2-disubstituted olefins is presented. Key to the success of this transformation was the introduction of a fluoride scavenger, trimethylsilyl trifluoromethanesulfonate (TMSOTf), to prevent a competitive -elimination pathway, as was the use of a phosphoramide ligand on selenium to promote the desired substitution reaction. A screen of catalysts revealed that more electron-rich phosphine ligands resulted in higher yields of the desired product, with selenophosphoramides giving the optimal results. A broad range of substrates and functional groups were tolerated and yields were generally good to excellent. For ()-1,2-disubstituted olefins, diastereoselectivities were always high, giving exclusively anti products. The conditions were also applied to substrates bearing internal nucleophiles such as esters and carbonates, giving rise to 1,2-aminoesters and cyclic carbonates, respectively.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7069249 | PMC |
http://dx.doi.org/10.1039/c9sc05335b | DOI Listing |
Chem Sci
February 2020
University of Washington, Department of Chemistry , Box 351700, Seattle , Washington 98195-1700 , USA . Email:
A new selenophosphoramide-catalyzed diamination of terminal- and -1,2-disubstituted olefins is presented. Key to the success of this transformation was the introduction of a fluoride scavenger, trimethylsilyl trifluoromethanesulfonate (TMSOTf), to prevent a competitive -elimination pathway, as was the use of a phosphoramide ligand on selenium to promote the desired substitution reaction. A screen of catalysts revealed that more electron-rich phosphine ligands resulted in higher yields of the desired product, with selenophosphoramides giving the optimal results.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!