Synthesis and Crystal Structure of a Chiral C3‐Symmetric Monophosphane

The C3-symmetric compounds 1 (R = H, tBu) are chiral phosphanes without a stereogenic C atom. A mutarotational energy of 11.8 kcal mol-1 was determined for the benzylphosphonium bromide of 1, R = H, by 1H-NMR spectroscopy. Resolution of the enantiomers was not achieved. Optically active C3-symmetric phosphane ligands are expected to exhibit good chiralitytransfer properties in transition-metal-catalyzed reactions.