Lithiation of tris(alkyl- and arylamido)orthophosphates EP[N(H)R]3 (E = O, S, Se): imido substituent effects and P=E bond cleavage

Octalithium, Tetrasodium, and Decalithium Compounds Based on Pyrrolyl Ligands: Synthesis, Structures, and Activation of the C-H Bonds of Pyrrolyl Rings and C═N Bonds of a Series of Ligands by Organolithium Reagents

The organometallic compounds of lithium ions have garnered continuous interest as indispensable precursors for the syntheses of organometallic complexes of main-group metals, transition metals, lanthanide metals, and actinide metals. In this work, we present a strategy for the preparation of a series of polynuclear lithium complexes. This methodology features the utilization of organolithium reagents both as metal sources to coordinate with the ligands and as nucleophilic reagents to undergo nucleophilic addition to the C═N bonds of the ligands. Reaction of a ligand HL1 [HL1 = 2-(((1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)methylene)amino)phenol] with n-BuLi produced complex [Li8(L1a)4]·1.5Tol (1·1.5Tol) [H2L1a = 2-((1-(1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)pentyl)amino)phenol]. One prominent feature regarding the formation of 1·1.5Tol is the occurrence of nucleophilic addition of n-BuLi to the C═N bond of HL1, leading to the generation of a new [L1a]2- ligand that contains both aminophenol and 1-(2-pyrrolyl)alkylamine scaffolds. The developed protocol can be adapted to a series of organolithium reagents. Compounds [Li8(L1b)4] (2) and [Li8(L1c)4] (3) were afforded by treatment of HL1 with sec-BuLi and LiCH2SiMe3, respectively. Reaction of an analogous ligand HL2 [HL2 = 2-(((1-(2-(dimethylamino)ethyl)-1H-pyrrol-2-yl)methylene)amino)-4-methylphenol] with n-BuLi generated compound [Li8(L2a)4] (4). C═N bond activation was not observed in the reaction of HL1 with NaOtBu, and the complex [Na4(L1)4]·Tol (5·Tol) was obtained. A decanuclear complex [Li10(L3a)2(L3b)2] (6) was also prepared via the reaction of HL3 [HL3 = 2-(2-((((1H-pyrrol-2-yl)methylene)amino)methyl)-1H-pyrrol-1-yl)-N,N-dimethylethan-1-amine] with t-BuLi. A remarkable feature in terms of the synthesis of 6 is the simultaneous occurrence of hydrogen atom abstraction from the C-H bond of the pyrrolyl ring and nucleophilic addition to the C═N bond of the HL3 ligand by t-BuLi. A series of amines containing biologically and physiologically important moieties were achieved by hydrolysis of the crude products from the reactions of the HL1-HL3 ligands and organolithium reagents. This work provides an efficient approach to high-nuclearity lithium compounds as well as a series of amines.

New synthetic strategies leading to [RNPNR]- anions and the isolation of the [P(Nt-Bu)3]3- trianion

New and straightforward synthetic paths for the syntheses of [RNPNR]- anions (R = t-Bu (1) or CPh3 (6)) in the form of their tmeda- or thf-coordinated lithium salts are described. The attempts to isolate the sodium analogue [(Ph3CNPNCPh3)Na·(thf)x] (8) remained unsuccessful probably due to its high reactivity although its formation in the reaction of the parent cis-[(Ph3CNP)2(Ph3CNH)2] (5) with 2 eq. of sodium naphthalenide was corroborated by NMR spectroscopy. Importantly, when an excess of sodium naphthalenide was used in the reaction with 5, [(Ph3C)Na(thf)3] (9) was obtained along with a complex mixture of other by-products indicating the cleavage of the C-N bond in the starting material. Furthermore, the synthesis and the structural characterization of the [P(Nt-Bu)3]3- trianion as its trilithium salt [P(Nt-Bu)3Li3]2 (10) has been successfully achieved.

A novel tubular hydrogen-bond pattern in a new diazaphosphole oxide: a combination of X-ray crystallography and theoretical study of hydrogen bonds

In the structure of 2-(4-chloroanilino)-1,3,2λ⁴-diazaphosphol-2-one, C₁₂H₁₁ClN₃OP, each molecule is connected with four neighbouring molecules through (N-H)₂...O hydrogen bonds. These hydrogen bonds form a tubular arrangement along the [001] direction built from R³₃(12) and R₄³(14) hydrogen-bond ring motifs, combined with a C(4) chain motif. The hole constructed in the tubular architecture includes a 12-atom arrangement (three P, three N, three O and three H atoms) belonging to three adjacent molecules hydrogen bonded to each other. One of the N-H groups of the diazaphosphole ring, not co-operating in classical hydrogen bonding, takes part in an N-H...π interaction. This interaction occurs within the tubular array and does not change the dimension of the hydrogen-bond pattern. The energies of the N-H...O and N-H...π hydrogen bonds were studied by NBO (natural bond orbital) analysis, using the experimental hydrogen-bonded cluster of molecules as the input file for the chemical calculations. In the ¹H NMR experiment, the nitrogen-bound proton of the diazaphosphole ring has a high value of 17.2 Hz for the ²J_H-P coupling constant.

Facile formation of stable tris(imido)phosphate trianions as their tri- and hexanuclear Pd(II) complexes in protic solvents

Employing Pd(OAc)2, a facile deprotonation route to access the highly basic tris(alkylimido)phosphate trianions, [(RN)3PO](3-) (R = (t)Bu, (c)Hex, or (i)Pr), analogous to the orthophosphate (PO4(3-)) ion in polar and in protic solvents has been achieved. Trinuclear and prismatic Pd(II) clusters of these imido trianions having the formula {Pd3[(NR)3PO](OAc)3}n (n = 1 or 2) or as mixed-bridged clusters of the type {Pd3[(N(i)Pr)3PO](OAc)2(OR')}2 (R' = Me or H) were isolated exclusively in all these reactions in which the trianionic species acts as a tripodal chelating ligand to the trinuclear Pd3 unit. Reactivity studies aiming at the Pd(II) atoms in these clusters with nucleophilic reagents, such as primary amines (R″NH2), have led to a new trimeric cluster with the formula {Pd3[(NR)3PO](OAc)3(R″NH2)3} in which the tripodal coordination of the Pd-Nimido moieties remained unaffected, exemplifying the robustness of the Pd3 unit in all these clusters. We have also shown the catalytic activity of these Pd(II) complexes in Mizoroki-Heck type coupling reactions in the presence of Cu(OAc)2.

Anion recognition and transport properties of sulfamide-, phosphoric triamide- and thiophosphoric triamide-based receptors

Studies of sulfamide, phosphoric triamide and thiophosphoric triamide-based organocatalysts show that the phosphorus containing systems are effective new hydrogen bonding motifs for the recognition and transport of anions.

O,O'-Dimethyl (cyclo-hexyl-amido)-thio-phosphate

The P atom in the title compound, C(8)H(18)NO(2)PS, is bonded in a distorted tetra-hedral PSO(2)N environment with bond angles in the range of 99.23 (5)-115.17 (4)°. The cyclo-hexane ring is disordered over two sets of sites with refined occupancies of 0.528 (5) and 0.472 (5). The ring in both disorder components adopts a chair conformation with the N-H group oriented equatorially. In the crystal, pairs of P=S⋯H-N hydrogen bonds form inversion dimers.

Synthesis, structure, and paramagnetism of manganese(II) iminophosphate complexes

The coordination chemistry of the bidentate bis(imino)bis(amino)phosphate ligands [Me(3)SiN═P{NR}{N(H)R}(2)](-), where R = n-propyl is [L(1)H(2)](-), R = cyclohexyl is [L(2)H(2)](-), and R = tert-butyl is [L(3)H(2)](-), with manganese(II), is described. The bis(imino)bis(amino)phosphate-manganese(II) complexes [(η(5)-Cp)Mn(μ-L(1)H(2))](2) (1), [Mn(L(2)H(2))(2)]·THF (2·THF), and [(η(5)-Cp)Mn(L(3)H(2))] (3) were synthesized by monodeprotonation of the respective pro-ligands by manganocene, Cp(2)Mn. The molecular structures of 1-3 reveal that the steric demands of the ligand N-substituents play a dominant role in determining the aggregation state and overall composition of the manganese(II) complexes. The coordination geometries of the Mn(II) centers are six-coordinate pseudotetrahedral in 1, four-coordinate distorted tetrahedral in 2, and five-coordinate in 3, resulting in formal valence electron counts of 17, 13, and 15, respectively. EPR studies of 1-3 at Q-band reveal high-spin manganese(II) (S = 5/2) in each case. In the EPR spectrum of 1, no evidence of intramolecular magnetic exchange was found. The relative magnitudes of the axial zero-field splitting parameter, D, in 2 and 3 are consistent with the symmetry of the manganese environment, which are D(2d) in 2 and C(2v) in 3.

Two newXP(O)[NHC(CH3)3]2phosphoramidates, withX= (CH3)2N and [(CH3)3CNH]2P(O)(O)

InN,N′-di-tert-butyl-N′′,N′′-dimethylphosphoric triamide, C10H26N3OP, (I), andN,N′,N′′,N′′′-tetra-tert-butoxybis(phosphonic diamide), C16H40N4O3P2, (II), the extended structures are mediated by P(O)...(H—N)2interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)2hydrogen bonds, givingR21(6) loops and forming two independent chains parallel to theaaxis. Of the 12 independenttert-butyl groups, five are disordered over two different positions with occupancies ranging from 1 \over 6 to 5 \over 6. In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)2hydrogen bonds giveS(6) andR22(8) rings, and the molecules form extended chains parallel to thecaxis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)2and (NH)2P(O)(O)P(O)(NH)2skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen-bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]x(x= 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)2P(O)(NH) and P(O)(NH)3fragments.

Diphenyl (p-tolyl-amido)-phosphate

The P atom in the title compound, C₁₉H₁₈NO₃P, exhibits a distorted tetra­hedral configuration while the N atom shows a planar coordination. In the crystal, inter­molecular N—H⋯O hydrogen bonds form centrosymmetric dimers.

New Architectures in Hydrogen Bond Catalysis

New achiral sulfamide, phosphoric triamide, and thiophosphoric triamide compounds have been synthesized. Their activity as hydrogen bond catalysts for the Friedel-Crafts and Baylis-Hillman reactions compares favorably with that of a known and active thiourea catalyst. The new compounds were also studied by X-ray crystallography and their solid state structures are described.

Solvent effects on the reactions of copper chlorides with OP(NH-t-Bu)3 — Formation of the novel [Cu5Cl10]5– anion via in situ templation

X-ray structural investigations have shown that the products of the reaction of CuCl2·2H2O and OP[NH-t-Bu]3 are markedly dependent on solvent and temperature. The polymeric ionic complex [(t-BuNH3)2(Cu3(OH)(H2O)Cl7)]∞ (1), containing a trinuclear anionic repeating unit, is obtained from toluene at 80 °C, whereas the 2:1 adduct Cu(t-BuNH2)2Cl2 (4) is formed at 150 °C. By contrast, a neutral tetranuclear cluster Cu4[PO(NH-t-Bu)3]4(µ4-O)Cl6 (2) or the one-dimensional chain [Cu(Py)2Cl2]∞ (3) is produced when the reaction is carried out in hexane or pyridine, respectively, at 80 °C. The reaction of a mixture of CuCl and CuCl2·2H2O (2:1 molar ratio) with OP[NH-t-Bu]3 at 80 °C in toluene produces [t-BuNH3]5[Cu5Cl10] (5), in which the anion is a pentanuclear cluster with both terminal and bridging chloride ions. The removal of the chloride ions from the reaction mixture by the addition of AgNO3 yields the 2:1 adduct Cu[OP(NH-t-Bu)3]2(NO3)2 (6).Key words: copper halides, templation, P–N compounds, cluster complexes, one-dimensional framework

Preparation, spectroscopic characterization, and deprotonation reactions of Si(NHR)4 (R = i-Pr, t-Bu, p-tolyl) — EPR identification of persistent radicals formed by oxidation of polyimidosilicates

Treatment of Cl2Si(NH-t-Bu)2 (6a) with t-BuNH2 in boiling toluene yields trisamino(chloro)silane ClSi(NH-t-Bu)3 (7); formation of the tetraaminosilane Si(NH-t-Bu)4 is not observed. The reaction of SiCl4 with 4 equiv. of LiNHR produces the corresponding tetraaminosilanes Si(NHR)4 (2a, R = i-Pr; 2b, R = t-Bu; 2c, R = p-tol) in good yields. When the sterically demanding adamantyl derivative LiHNAd is employed, only disubstitution occurs to form Cl2Si(NHAd)2 (6b). Oxidation of the dimeric imidosilicates {Li3[Si(NR)3(NHR)]·THF}2 (3a, R = i-Pr; 3b, R = t-Bu) with 1 mol of iodine produces the persistent radicals {Li2[Si(NR)3(NHR)]·LiI·3THF}·, which, on the basis of EPR spectra, exist as SiN3Li3I cubes in solution. The spirocyclic tetraimidosilicate monoanion radical {[(THF)2Li(µ-Nnaph)2Si(µ-Nnaph)2Li(THF)2]}–· (10) is formed upon oxidation of the tetralithiated species {Li4[Si(Nnaph)4]·4Et2O} (1) and {[Li(12-crown-4)]2[(Et2O)2Li(µ-Nnaph)2Si(µ-Nnaph)2Li(Et2O)2]} (8) with iodine. The spectroscopic characterization of hexa(amino)disiloxane (t-BuNH)3SiOSi(NH-t-Bu)3 (14) formed from the reaction of Cl3SiOSiCl3 with 6 equiv. of LiNH-t-Bu is discussed. Key words: imido ligands, silicate, radicals, EPR spectra, lithium.

Synthesis and structural characterization of zinc complexes of the imido–amido phosphate anions OP[(NHR)3–x(NR)]x– (R = Me, t-Bu; x = 1–3) and EP[(NH-t-Bu)2(N-t-Bu)]– (E = S, NSiMe3)

The reaction of OP(NH-t-Bu)3 with 1 equiv. of ZnMe2 generates the dimeric eight-membered ring {MeZn[(µ-NH-t-Bu)(µ-N-t-Bu)P(NH-t-Bu)(µ-O)]}2 (5) and the cubane {[MeZn]3[OP(N-t-Bu)3][OP(NH-t-Bu)3]} (6), which contains the first known trisimidophosphate trianion. A related complex {Zn[ZnMe]2[OP(N-t-Bu)(NH-t-Bu)2][OP(N-t-Bu)3]} (7) is obtained by the reaction of OP(NH-t-Bu)3 with ZnMe2 in a 2:3 molar ratio. The treatment of OP(NHMe)3 with 1 equiv. of ZnMe2 produces the oxide-templated cluster {Zn4(µ4-O)[OP(NMe)(NHMe)2]4[OP(NMe)2(NHMe)]}2 (8). Each half of this centrosymmetric dimer contains a tetrahedral arrangement of four 4-coordinate Zn2+ ions surrounding the central µ4-O2- anion. The reaction of SP(NH-t-Bu)3 with ZnMe2 in a 1:1 molar ratio generates the dimer {MeZn(µ-S)(µ-N-t-Bu)P(NH-t-Bu)2}2 (10), which has a ladder-type structure. When a 2:1 molar ratio of the same reagents is employed, the bis(N,S)-chelated complex {Zn[(µ-S)(µ-N-t-Bu)P(NH-t-Bu)2]2} (11) is obtained. The monomeric N,N′-chelated complex {MeZn[(µ-N-t-Bu)(µ-NSiMe3)P(NH-t-Bu)2]} (12) results from the reaction of Me3SiNP(NH-t-Bu)3 with 1 equiv. of dimethylzinc. All new compounds have been characterized by multinuclear (1H, 13C, and 31P) NMR spectroscopy and, in the case of 5, 6, 7, 8, and 10, by X-ray structural determinations.Key words: zinc, phosphate, imido ligands, sulfur.

Structure and magnetic properties of a novel copper halide framework {[tBuNH3]2[Cu3(µ3-OH)(µ2-H2O)Cl7]}n synthesized via in situ templation

The use of the tris(alkylamido)phosphate OP[N(H)tBu]3 as an in situ source of the templating agent [tBuNH3]+ produces the copper halide chain {[tBuNH3]2[Cu3(mu3-OH)(mu2-H2O)Cl7]}n (1) in a solvothermal process; the novel antiferromagnetically coupled trinuclear fragment Cu3(OH)(H2O)Cl7 is the building block in the polymeric anion in .

First transition-metal complexes of SP(NHBut)3

The first transition-metal (Rh(I), Mo(VI), Ni(II)) complexes of S[double bond, length as m-dash]P(NHBu(t))(3) have been synthesized via metathetical reactions of mono-lithiated and [Rh(CO)(2)Cl](2), (Bu(t)N)(2)MoCl(2)(dme) and NiBr(2)(dme). Surprisingly in the molecular structure of the Ni(II)-complex both hard-soft (N,S) and hard-hard (N,N[prime or minute]) chelation modes of are realized.