Diphosphine derivatives of urea and thiourea

Novel organo phosphorus–selenium heteroatom compounds from selenation of diamines

“…The synthesis and X-ray structure of compound 8 has been reported previously. 24 Heterocycles 3 and 9 are quite stable as solids and in solution in air and moist atmospheres, and are soluble in normal organic solvents. Both compounds were fully characterized by 1 H, 13 C, 31 P and 77 Se NMR, IR spectroscopy, mass spectrometry.…”

“…Crystal data and details of the structure determination are given in The structure of 10, in contrast to the reported similar structures which are essentially planar, 12 has a five-membered P-N-C-C-N ring which is significantly distorted from planar. The P=Se distance (2.0895(16) Å) is normal, [24][25][26][27] while the P-N bond lengths (1.682(5) and 1.658(5) Å) are significant shorter than the typical P-N single bond length (1.77 Å) but much longer than the normal P=N double bond (1.57 Å) 30 indicating some multiple bond character present in this structure. The internal N-P-N angle (N(1)-P(1)-N(2) 93.9(2) of the five membered P-N-C-C-N ring is slightly bigger than the smallest angle [91.34 (14) [35] indicating delocalisation of the negative charge over the PSe 2 fragment.…”

Synthesis of Novel Vinylic P–Se Heterocycles from Selenation of Alkynes by [PhP(Se)(μ‐Se)]2

“…For 2, the mean deviation of the Se(1)-C(7)-P(1)-C(8)-Se(2) plane is 0.13 Å, while in 3 the value is 0.25 Å, the extra deviation from planarity in 3 is also evident in a contraction of the P(1)-Se(2)-Se(3) and C(8)-P(1)-Se(2) internal angles on going from 2 to 3 [92.18(3)°a nd 101.02(12)°for 2, 89.56(5)°and 98.6(2)°for 3] and both effects probably reflect the steric influence of the phenyl group in 3 compared to a hydrogen atom in 2. The majority of the other geometric parameters in these two compounds are similar, thus the exocyclic P(1)-Se (1) [8,9,[15][16][17][18]20] The C(7)-C (8) www.eurjic.org [a] Dimensions for second independent molecule in square parentheses.…”

“…[10][11][12][13] We have also reported the use of FcP(S)S 2 P(S)Fc (Fc = ferrocenyl) and WR in the preparation of novel metal complexes, C-P-S and C-P-Se heterocycles by reaction with a variety of reactive organic substrates/functionalities including CS 2 , C=O, C=C double bond and CϵN triple bonds. [8,[14][15][16][17][18][19] To date, no general method for the synthesis of vinylic selenium-containing heterocycles has been established. We have focused our attention on the preparation of a series of novel vinylic heterocycles by reaction of WR with alkynes and here describe a series of new heterocycles.…”

How Not to Discover a New Reagent. The Evolution and Chemistry of Woollins' Reagent

“…WR reacts with trinorbornene in refluxing toluene to give a five-membered C 2 PSe 2 ring (confirmed by X-ray crystallography). 58 However, reaction of WR with trinorboradiene yields the five-membered C 2 PSe 2 ring and a four-membered C 2 PSe heterocycle analogous to the thiaphosphetane (C 2 PS) rings (Scheme 14). 43 Reaction of WR with azobenzene 58 gives a PSe 2 N heterocycle (eqn 8)…”