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Bis(methylene)phosphorane and Related Compounds: Electrocyclization to Ring Systems
Author(s) -
Schoeller Wolfgang W.,
Busch Thilo
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921250604
Subject(s) - phosphorane , chemistry , electronegativity , methylene , ring (chemistry) , ab initio , allylic rearrangement , crystallography , computational chemistry , ab initio quantum chemistry methods , steric effects , stereochemistry , molecule , medicinal chemistry , organic chemistry , catalysis
On the bais of ab initio calculations of double‐ζ quality at a SCF and MCSCF level, bonding in bis‐ylenephosphoranes is compared with the one in phosphoranes. The investigations include the series H 3 PX, HPX 2 , HPX (X = CH 2 , NH, O, SiH 2 , PH, S). The bis‐ylenephosphorane formation becomes more favorable with increasing electronegativity of X. An extreme case is the electropositive group X = SiH 2 . The resulting π‐system suffers from the Jahn‐Teller distortion, causing reduction from C 2v to lower C 2 symmetry in the corresponding bis‐ylenephosphorane. Energetically, the corresponding ring systems are more stable than their bis‐ylenephoshorane counterparts (for X = CH 2 and PH). The electronic hypersurface of the hitherto unknown bis(phosphinylidene)phosphorane is explored in detail and compared in regard to bonding with its analog bis(methylene)phosphorane. For both cases π‐push‐pull substitution is important for stabilization of the planar allylic geometry.