Cyclic sulfur nitrogen compounds and phosphorus reagents: Part XII. Reactions of S₄N₄ with (2‐pyridylamino) phosphines [1]

Abstract

ABSTRACT

A new synthetic route to cyclophosphadithiatriazenes: synthesis and X‐ray structural characterization of the first spirocycle containing thiadiazaphosphetidine and phosphadithiatriazene heterocycles

“…However, the yield was found to be higher compared with other available synthetic routes. 21,23,28,30 Attraction of a sulfur atom from S 4 N 4 by the attacking phosphine (highly thiophilic in nature; two moles of phosphine are added during the…”

“…34 Prompted by the realization of a stable addition product at 1,3-sulfur positions of the PS 2 N 3 heterocycles reported earlier, 23 adduct formation reaction was attempted with the strained olefin, norbornadiene (NBD). The band at 603 nm vanishes upon derivatization with norbornadiene which conforms with previous observations and the accompanying change in the π -manifold of the inorganic heterocycle (that is, 8π → 6π ).…”

“…The endocyclic P-N bonds in the PS 2 N 3 heterocyclic part are distinctly shorter and appear to be slightly shorter compared with the corresponding distances in similar structures available in literature. 21,23,53 The bonding parameters of PS 2 N 3 part of spirocycle have been compared (Table 2) with the three other structures of this type reported so far. The S-N bonds of the unsaturated ring are of two kinds [1.5906(11) and 1.6209 (14)´Å], unlike in the reported structures, 21,23 where the bond distances are approximately same.…”

“…21,23,53 The bonding parameters of PS 2 N 3 part of spirocycle have been compared (Table 2) with the three other structures of this type reported so far. The S-N bonds of the unsaturated ring are of two kinds [1.5906(11) and 1.6209 (14)´Å], unlike in the reported structures, 21,23 where the bond distances are approximately same. Interestingly, endocyclic bond length variation in case of (Me 3 SiNH) 2 PS 2 N 3 does not present a discernable trend.…”

“…21,28 -30 In all cases, the syntheses were restricted to the preparation of R 2 PS 2 N 3 where R = Ph, PhO, CF 3 , C 2 F 5 and Me 3 SiNH. In the early 1990s, Rao and coworkers 23 reported a new route for synthesizing monoamino derivatives of phosphathiazene heterocycles starting from 2-aminopyridyl phosphine derivatives and tetrasulfur tetranitride, S 4 N 4 . They succeeded in preparing (Ph)[(C 6 H 11 ) 2 N]PS 2 N 3 , which was the first example of heterocycle bearing two different substituents.…”