Dimerization of Intermediate P+–C–O– Dipolar Ions into Carbaphosphatrane Derivatives during Intramolecular Cyclization of 2-R-4,4-Bis(trifluoromethyl)benzo[f][1,3,2]dioxaphosphepin-5-ones

• Published in: Russian journal of organic chemistry Vol. 58; no. 8; pp. 1099 - 1107
• Main Authors: Mironov, V. F., Ivkova, G. A., Litvinov, I. A., Islamov, D. R., Khayarov, Kh. R.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2022; PLEIADES PUBLISHING LTD; Springer Nature B.V
• Subjects: Carbonyl groups; Carbonyls; Chemistry; Chemistry and Materials Science; Chemistry, Organic; Dimerization; Electronegativity; Organic Chemistry; Oxygen atoms; Physical Sciences; Science & Technology; cage phosphorane; dioxaphosphepine; dimerization; carbaphosphatrane; P–C–O dipolar ion; benzo-1,2-oxaphosphole; trigonal bipyramide; hydrolysis; apicophilicity; CAGE; P-C-O dipolar ion; CRYSTAL-STRUCTURE; benzo-1; 2-oxaphosphole
• ISSN: 1070-4280; 1608-3393
• DOI: 10.1134/S107042802208005X

2-R-4,4-Bis(trifluoromethyl)benzo[ f ][1,3,2]dioxaphosphepin-5-ones containing an endocyclic carbonyl group, when stored or slightly heated, undergo spontaneous intramolecular cyclization into P + –C–O – -bipolar ions containing benzoxaphosphole and oxaphosphethane rings fused along the P–C bond. These ions further dimerize into carbaphosphatrane derivatives with a pentacoordinate phosphorus atom, where the P–C bond is incorporated simultaneously into four-, five-, and six-membered rings. Hydrolysis of the carbaphosphtranes leads to the formation of benzo[ d ][1,2]oxaphosphole derivatives. The structure of one of the carbaphosphatranes, as well as one of the benzo[ d ][1,2]oxaphospholes has been proved by X-ray diffraction analysis. Carbon substituents in the carbaphosphatrane occupy apical positions, whereas the more electronegative oxygen atoms are in equatorial positions.