Novel organo phosphorus–selenium heteroatom compounds from selenation of diamines

Reaction of Woollinsʹ reagent (WR) with trans-1,2-cyclohexanediamine or 1,3-cyclohexanediamine, followed by treatment with o-xylylenedibromide in THF at room temperature surprisingly led to 3-phenyl-1,5-dihydrobenzo[e][1,3,2]diselenaphosphepine 3-selenide (3). However, using o-phenylenediamine, the same product together with 1,4-dihydrobenzo[d][1,2]diselenine (9) was obtained. Furthermore, treating WR with N,N′-dibenzylethane-1,2-diamine gave rise to 1,3-dibenzyl-2-phenyl-1,3,2-diazaphospholidine 2-selenide (10) and a zwitterionic product N-benzyl-N-(2-(benzylammonio)ethyl)-P-phenylphosphonamidodiselenoate (11). Unexpectedly, WR reacted with 2,2′-disulfanediyldianiline under identical conditions affording the known product: 2-phenyl-2,3-dihydrobenzo[d][1,3,2]thiazaphosphole 2-selenide (13). Three representative X-ray structures are reported.