Collect. Czech. Chem. Commun. 2000, 65, 570-576

C3-Symmetric Azaphosphatranes

Fredrik Lake, Lars Hagberg, Mats Svensson and Christina Moberg*

Department of Chemistry, Organic Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden


C3-Symmetric azaphosphatranes, (3S,7S,10S)-2,3,7,8,9,10-hexamethyl-2,8,9-triaza-5-azonia-1-λ5-phosphabicyclo[3.3.3]undecane chloride and (3S,7S,10S)-3,7,10-triisopropyl-2,8,9-trimethyl-2,8,9-triaza-5-azonia-1-λ5-phosphabicyclo[3.3.3]undecane chloride, have been prepared starting from the corresponding chiral tripodal tetraamines and chlorobis(diethylamino)phosphane. The compounds are weak acids which are not fully deprotonated by potassium tert-butoxide. Density functional calculations of the compounds and their conjugate bases demonstrate that the weak acidity originates in a conformational change upon deprotonation leading to substantial steric repulsion.

Keywords: Azaphosphatranes; C3 Symmetry; Chirality; Basicity; Quantum chemistry; DFT calculations.

References: 27 live references.