Von Ketazinen zu 1,2-Diaza-3-phospha-cyclopent-5-enen, -penta-3,5-dienen, 1,5-Diaza-2,6-diphospha-bicyclo[3.3.0]octa-3,7-dien und einem Cyclohexaphosphan / From Ketazines to 1,2-Diaza-3-phospha-cyclopent-5-enes, -penta-3,5-dienes, 1,5-Diaza-2,6-diphospha-bicyclo[3.3.0]octa-3,7-dien, and Cyclohexaphosphane

Abstract

Abstract The dilithium salt of di(tert-butyl-methyl)ketazine 1 reacts with the bimolar amount of ClSiMe3 to give the di(tert-butyl-trimethylsilylmethylen)ketazine, 2. In the reaction of lithiated 2 and F2PN(iPr)2 the 1,2-diaza-3-phosphacyclopent-5-ene (3) is formed. The dichlorophosphanes Cl2PC6H5 and Cl2PCMe3 react with 1 in boiling toluene to give the 1,2-diaza-3-phosphacyclopentenes 4 and 5. The oxygen of the air oxidizes 5 to the 1,2-diaza-3-phosphacyclopent-5-ene 6. Equivalent amounts of H2O cleave the ring skeleton of 5, the tert-butyl-methyl-(tert-butyl-(tert-butylphosphino)methylketazine 7 being formed. The 1,2-diaza-3-phosphacyclopenta-3,5-diene 8 and the 1,5-diaza-2,6-diphospha- bicyclo[3.3.0]octa-3,7-diene 9 are the reaction products of 1 and PCl3 in toluene. 1 forms with HCl the hydrochloride 10. The 5-tert-butyl-1,2-diaza-3-phospha-cyclopenta-3,5-diene 11 is isolated from the reaction of 9 and MeLi. 11 is also obtained from PCl3 and tert-butyl-methyl-hydrazone in good yields. The cyclohexaphosphane 12 was formed in the reaction of 9 with Na/K alloy. The results of the crystal structure analyses of 2, 3, 6, 10, and 12 are reported.