STEREOSPECIFIC FORMATION OF A 1,2λ3 -AZAPHOSPETANE IN THE THERMOLYSIS OF BIS[BIS(DIISOPROPYLAMINO)PHOSPHANYL] DIAZOMETHANE

Abstract

Heating of bis[bis(diisopropylamino)phosphanyl]diazomethane 7. in refluxing benzene for 48 hours, quantitatively led to the corresponding 1.2λ³-azaphosphetane 9 as only one diastereoisomer. This result is explained in terms of carbene insertion into a methin-CH bond of an isopropyl substituent. The regiospecificity and the stereospecificity of the ring closure is discussed. Treatment of 9 with elemental sulfur afforded the corresponding 1.2.2λ³-azathiophosphetane 10 which has been characterized b X ray crystallo raphy: C₂₅H₅₆N₄P₂S₂, space group P2(l)/n, a = 13.628 (3) Å, 6 = 19.369 (5) Å, c 112.485 (4) Å, V = 3073 (3) ų.