Synthesis and structural study of novel selenation derivatives of N, N-Dialkylcyanamides

The reaction of 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide {[PhP(Se)(µ-Se)]₂, Woollins’ reagent, WR} with N, N-dialkylcyanamides 1–3 in refluxing toluene solution led to the corresponding [2+3] cycloaddition products 4-dialkylamino-2,5-diphenyl-1,3,2,5-selenazadiphosphole 2,5-diselenides 4–6 in good yields, the latter were further treated with water resulting in the corresponding hydrolysis derivatives dialkyl-selenoureas 7–9, and phosphinodiselenoates 10 and 11. Selenourea 7 could be transferred into 1,3-selenazol-2-amines 12–15 in excellent yields by further cyclization with four different α-haloketones. All new compounds have been characterized by IR spectroscopy, multi-NMR (¹H, ¹³C, ³¹P, ⁷⁷Se) spectroscopy and accurate mass measurement. The single crystal X-ray structural features of nine new compounds are also discussed.