The use of chiral phosphine ligands to impart chirality to a metal center is ubiquitous in chemistry, particularly in asymmetric catalysis; however, the synthesis and purification of chiral phosphines can be quite challenging. It is possible to create a chiral metal center using achiral ligands that is “chiral-at-metal”. The chiral-at-metal compound is unique because the ligand that is creating the metal stereocenter is not chiral itself. Our research goal was to prepare chiral metal complexes using this non-traditional route in order to synthesize catalysts capable of asymmetric catalysis, but without some of the synthetic challenges that lie with manipulating chiral phosphines. This work focuses on the synthesis of achiral, unsymmetric, bidentate ligands using secondary phosphine oxides as cheap, air-stable, and abundant starting materials. The goals of this project were to prepare ligands with two different phosphine groups, as well as compounds bearing both a phosphine and an N-heterocyclic carbene (NHC); this type of unsymmetric ligand can provide chirality to metal complexes and may be able to provide interesting steric, electronic, and catalytic properties. Thus far, a number of novel bis-bidentate ligands have been prepared and characterized, and a select number of transition metal complexes have been characterized, including a single crystal X-Ray structure for a Pt(II) complex bearing a Me2P(CH2)3P(i-Pr)2 ligand.

Synthesis of unsymmetrical bidentate ligands from secondary phosphine oxides for "chiral-at-metal" complexes

2019 Spring National Meeting

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