Lithiation of Tris(alkyl- and arylamido)orthophosphates EP[N(H)R]₃ (E = O, S, Se):  Imido Substituent Effects and PE Bond Cleavage

Abstract

In the solid state, OP[N(H)Me](3) (1a) and OP[N(H)(t)Bu](3) (1b) have hydrogen-bonded structures that exhibit three-dimensional and one-dimensional arrays, respectively. The lithiation of 1b with 1 equiv of (n)BuLi generates the trimeric monolithiated complex (THF)[LiOP(N(t)Bu)[N(H)(t)Bu](2)](3) (4), whereas reaction with an excess of (n)BuLi produces the dimeric dilithium complex [(THF)(2)Li(2)OP(N(t)Bu)(2)[N(H)(t)Bu]](2) (5). Complex 4 contains a Li(2)O(2) ring in an open-ladder structure, whereas 5 embraces a central Li(2)O(2) ring in a closed-ladder arrangement. Investigations of the lithiation of tris(alkyl or arylamido)thiophosphates, SP[N(H)R](3) (2a, R = (i)Pr; 2b, R = (t)Bu; 2c, R = p-tol) with (n)BuLi reveal interesting imido substituent effects. For the alkyl derivatives, only mono- or dilithiation is observed. In the case of R = (t)Bu, lithiation is accompanied by P-S bond cleavage to give the dilithiated cyclodiphosph(V/V)azane [(THF)(2)Li(2)[((t)BuN)(2)P(micro-N(t)Bu)(2)P(N(t)Bu)(2)]] (9). Trilithiation occurs for the triaryl derivatives EP[N(H)Ar](3) (E = S, Ar = p-tolyl; E = Se, Ar = Ph), as demonstrated by the preparation of [(THF)(4)Li(3)[SP(Np-tol)(3)]](2) (10) and [(THF)(4)Li(3)[SeP(NPh)(3)]](2) (11), which are accompanied by the formation of small amounts of 10.[LiOH(THF)](2) and 11.Li(2)Se(2)(THF)(2), respectively.

Organic Cation and Complex Cation‐Stabilized (Poly‐)Selenides, [Cation]x(Sey)z: Diversity in Structures and Properties

“…[33] In combination with an only threefold coordination of the Li + ion, this compound would probably be classified as a selenidolithiate. [34] We were [37] (c), [Ni(tren) 2 ](Se 3 ) (c) (tren = diethylene triamine), [38] [Mn(en) 3 ](Se 3 ) [39] [42] [Ba(en) 4 ](Se 4 )·en (c), [43] and [Ca(en) 4 ](Se 4 ) [44] (c) clearly belong to organic cation-stabilized selenides, although Fässler and Menezes discuss a 3D network due to interconnecting hydrogen bridges. Dimorpholine and dipiperidine tetraselanes should be excluded from this list, although they are sometimes quoted in literature as (NC 4 H 8 O) 2 (Se 4 ), (NC 5 H 10 ) 2 (Se 4 ).…”

Synthesis and Structures of Aluminum and Magnesium Complexes of Tetraimidophosphates and Trisamidothiophosphates: EPR and DFT Investigations of the Persistent Neutral Radicals {Me2Al[(μ-NR)(μ-NtBu)P(μ-NtBu)2]Li(THF)2}• (R = SiMe3, tBu)

“…The chemical and physical properties of these polyimido anions are dependent in large part upon the ratio of imido:oxo units and the size of the imido substituent. 1 Numerous analogues of phosphorus oxo-anions have been prepared, 3 including the trisimido(meta)phosphate 4 Previously we have thoroughly investigated the reactivities of a series of trisaminophosphates OP(NH t Bu)3 (1), 6,8 SP(NHR)3 (2a, R = t Bu; 2b, R = i Pr; 2c, R = ptol) 8,10 and (RNH)3PNSiMe3 (3a, R = t Bu; 3b, R = Cy) 6, 11 toward alkyllithium reagents.…”

Synthesis, Spectroscopic Study and Crystal Structure of a New Amidophosphonate, (C₆H₅O)₂P(O)(NHCH(CH₃)(C₂H₅))

“…Phosphorus-containing compounds play a vital role in different domains of chemistry, 1 because of their applications in medicine and pharmacology, 2,3 coordination chemistry 4,5 and biochemistry. 6 Recently, crystal structures of some phosphoramides have been reported.…”