Absolute Configuration of tert-Butyl-1-(2-methylnaphthyl)phosphine Oxide

Citations Over TimeTop 11% of 2002 papers

Abstract

The enantiomers of tert-butyl-1-(2-methylnaphthyl)phosphine oxide 1 have been separated using a homemade HPLC column and an analytical gradient system. Vibrational absorption and circular dichroism spectra for both enantiomers have been measured in CD2Cl2 and CH2Cl2 solutions in the 2000-900 cm(-1) region. The fully relaxed potential energy surface of (S)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide, obtained using the B3LYP functional with a 6-31G basis set, indicated two stable conformers with their populations in a approximately 2:1 ratio. The vibrational absorption and VCD spectra are predicted for these two conformers using the B3LYP functional with a 6-31G basis set. The comparison of predicted and experimental spectra indicated that (+)-tert-butyl-1-(2-methylnaphthyl)phosphine oxide is in the (S)-configuration. This assignment is supported by the ab initio prediction of positive optical rotation for the most stable conformer with an (S)-configuration and the nonequivalence sense of the tert-butyl group chemical shift observed in the 1H NMR spectrum of this enantiomer measured in the presence of (+)-(S)-mandelic acid as a chiral solvating agent.

Related Papers

• → Optically active phosphine oxides. 8(1989)33 cited
• → Synthesis of New Chiral Crown Ethers Containing Phosphine or Secondary Phosphine Oxide Units(2020)6 cited
• → Thermal stability of primary and secondary phosphine oxides formed as a reaction of phosphine oxide with ketones(2016)9 cited
• → Molecular structure of (3,5-diallylisocyanuratomethyl)bis(chloromethyl)phosphine oxide. Synthesis of (3,5-diallylisocyanuratomethyl)phosphine sulfides(1993)2 cited
• Immobilization of Ferrocenyl Phosphine Tethered to Merrifield Resin(2011)