A Chiral Amide Derivative with the β‐P4S3 Cage Skeleton

The diamide exo, exo‐β‐P₄S₃(NHCH(Me)Ph)₂ has been made in solution using enantiomerically pure or racemic PhCH(Me)NH₂, and its three diastereomers characterised by complete analysis of their ³¹P{¹H} NMR spectra.The unsymmetric diastereomer contains phosphorus atoms, made chemically non‐equivalent by the chirality of the substituents, which show a large ²J(P—P—P) coupling to each other (225.2 Hz).     

Phosphorus NMR and Ab Initio Modelling of P–N Bond Rotamers of a Sterically Crowded Chiral β‐P4S3 Diamide

Reaction of bicyclic β‐P₄S₃I₂ with enantiomerically pure (R)‐Hpthiq (1‐phenyl‐1,2,3,4‐tetrahydroisoquinoline) and Et₃N gave a solution of a single diastereomer of the unusually stable diamide β‐P₄S₃(pthiq)₂, accounting for 83 % of the phosphorus content. Despite the steric bulk of the substituents, each amide group of this could adopt either of two rotameric positions about their P–N bonds, so that, at 183 K, ³¹P NMR multiplets for four rotamers could be observed and the spectra of three of them analysed fully. The large ²J(P–P–P) coupling became greater (253, 292, 304 Hz) with decreasing abundance of the individual rotamers. The rotamers were modelled at the ab initio RHF/3–21G* level, and relative NMR chemical shifts predicted by the GIAO method using a locally dense basis set, allowing the observed spectra to be assigned to structures. Calculations at the same level for the model compound α‐P₄S₃(pthiq)Cl confirmed the assignments of low‐temperature rotamers of α‐P₄S₃(pthiq)I reported previously. Changes in observed P–P coupling constants and ³¹P chemical shifts, on rotating a pthiq substituent, could then be compared between β‐P₄S₃(pthiq)₂ and α‐P₄S₃(pthiq)I, confirming both sets of assignments. The most abundant rotamer of β‐P₄S₃(pthiq)₂ was not the one with the least sterically crowded sides of both pthiq substituents pointing towards the P₄S₃ cage, because of interaction between the two substituents. Only by using a DFT method could relative abundances of rotamers of β‐P₄S₃(pthiq)₂ be predicted to be in the observed order. Use of racemic Hpthiq gave also the two diastereomers of β‐P₄S₃(pthiq)₂ with C_s symmetry, for which the room temperature ³¹P{¹H} NMR spectra were analysed fully.     

Phosphorus NMR Characterisation of P–N Bond Rotamers of a α‐P4S3 Amide with a Conformationally Constrained Chiral Substituent

Reactions of bicyclic α‐P₄S₃I₂ with Hpthiq gave solutions containing α‐P₄S₃(pthiq)I and α‐P₄S₃(pthiq)₂, where Hpthiq is the conformationally constrained chiral secondary amine 1‐phenyl‐1,2,3,4‐tetrahydroisoquinoline. The expected diastereomers have been characterised by complete analysis of their ³¹P{¹H} NMR spectra. Hindered P–N bond rotation in the amide iodide α‐P₄S₃(pthiq)I caused greater broadening of peaks in the room‐temperature spectrum of one diastereomer than in that of the other. At 183 K, spectra of two P–N bond rotamers for each diastereomer were observed and analysed. The minor rotamers showed strong evidence for steric crowding, having large diastereomeric differences in ¹J(P–P) and ²J(P–S–P) couplings (49 Hz, 16 % of value, and 4.4 Hz, 19 % of value, respectively).     

洗涤剂中含磷化合物的31PNMR快速检测方法

收集了常见的31种含磷无机化合物和84种含磷有机化合物,首次建立了含磷化合物的核磁共振谱图库,并以此为依据建立了31P NMR技术快速检测洗涤剂中含磷化合物的方法.对洗衣粉、金属清洗剂和除油剂样品进行31P NMR分析,经与31P谱图库比对,可快速确定含磷化合物的结构.结果表明,10种洗衣粉中仅有1种检出含磷化合物,其...     

Assignment of Phosphorus NMR Parameters to Absolute Configurations in Chiral Phosphorus Sulfide Cage Compounds,using Ab Initio Methods

The closo cage molecules α‐ and β‐P₄S₃(μ‐NCH(Me)Ph) were modelled at the RHF/3‐21G* and MPW1PW91/DZVP levels. For each, the conformational space corresponding to rotation about the C–N bond was explored, and relative average electronic energies were calculated. The β‐isomer was more stable than the α‐isomer by 10.7 kJ mol^?1, according to the DFT calculations, in contrast to the unsubstituted model compounds α‐ and β‐P₄S₃(μ‐NH), where the α‐isomer was more stable. GIAO calculations of phosphorus isotropic NMR shieldings, in the rotamers, led to relative average chemical shifts in the diastereomers. Comparison with experimental chemical shift differences gave an assignment to absolute configuration for α‐P₄S₃(μ‐NCH(Me)Ph), which agreed with the assignment obtained by comparing calculated relative diastereomer stability with observations. For β‐P₄S₃(μ‐NCH(Me)Ph), the GIAO calculations allowed relative assignment of observed chemical shifts to the nitrogen bridgehead phosphorus atoms.     

In situ Synthesis of Rosin Derived Chiral Derivatizing Agents for 31P NMR Assays of Amine and Alcohol Enantiomers

Chiral alcohols(3, 5) were synthesized in optically pure forms from easily available rosin acid in short-steps. A comprehensive protocol for the enantiomeric excess assays of mono-or difunctional-grouped chiral secondary amine or alcohol has been established with them used as chiral auxiliary for chiral phosphorus derivatizing agents(CPDAs) in ³¹P NMR tests. Chemical shift difference(Δδ_P) values ranging from 4.5 to 0.15 between two diastereoisomers of the CPDAs and the aryl substrates were obtained. Positive Δδ_R-S was observed for all the tested alcohol P(III) and P(V) derivatives, while negative Δδ_R-S was observed for all the amines.     

α‐Tetraphosphorus Trichalcogenide Diamides and Imides containing both Sulfur and Selenium

Reaction of a mixture of bicyclic phosphorus sulfide selenide iodides α‐P₄S_nSe_3−nI₂ (n = 0–3) with PrⁱNH₂ and Et₃N gave corresponding diamides α‐P₄S_nSe_3−n(NHPrⁱ)₂ (n = 0–3) and imides α‐P₄S_nSe_3−n(μ‐NPrⁱ) (n = 2–3), identified in solution by ³¹P NMR. In one isomer of α‐P₄S₂Se(μ‐NPrⁱ), the C₂ symmetry of imides such as α‐P₄S₃(μ‐NPrⁱ) was broken, allowing relative assignment of ²J NMR couplings to the PNP bridge and the PSP bridge opposite to it. The coupling through the sulfur bridge was found to be reduced to ca. zero, in contrast to previous assumptions for this class of compounds. Ab initio models were calculated at the MPW1PW91/svp level for the sulfide selenide imides and for a selection of bond rotamers of the diamides, and at the MPW1PW91/LanL2DZ(d) level for the sulfide selenide diiodides. Different skeletal isomers were prevalent for the mixed chalcogenide diamides than for the diiodides, showing that exchange of chalcogen between skeletal positions took place in the amination reaction even at room temperature. Similar differences to those observed were predicted by the models, suggesting that equilibrium was attained.     

不同pH条件下典型有机磷核磁图谱差异性解析

液相磷-31核磁共振波谱技术(31PNMR)是当前国内外土壤有机磷(Po)分子形态表征的主流分析技术,其主要利用乙二胺四乙酸-NaOH溶液提取,然后在高pH值(pH=13)条件下采集谱图.然而,高pH值条件下P.可能水解,同时鉴于实际土壤pH值通常在6～8范围内,因此有必要探究pH值对P.核磁谱图的影响.对D-葡萄糖-...     

用于芳香胺和醇NMR对映体检测的松香基膦试剂的合成

以松香为原料通过三步反应高产率合成手性二醇3和手性单醇6,将它们用作手性助剂现场制备有机膦衍生试剂,分别对单官能团手性底物(单胺、单醇)和双官能团底物(双胺、双醇及氨基醇)进行衍生,通过31P NMR测定,其芳基底物非对映体衍生物的膦化学位移差异值(Δδp)在3.08～0.10之间,均能够在测定条件下实现对映体峰的基线分离.用于α-萘乙胺和1,1’-联二萘酚(BINOL)样品对映体过量值测定,相对误差小于±2%.     

Bildung und Strukturen von [{η2‐tBu2P–P=P–PtBu2}Pt(PR3)2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XVIII. Syntheses and Structures of [{η²‐^tBu₂P–P=P–P^tBu₂}Pt(PR₃)₂] ^tBu₂P–P=P(Me)^tBu₂ reacts with [{η²‐C₂H₄} · Pt(PR₃)₂] as well as with [{η²‐^tBu₂P–P}Pt(PR₃)₂] yielding [{η²‐^tBu₂P–P=P–P^tBu₂}Pt(PR₃)₂]; PR₃ = PMe₃ 3 a , PEtPh₂ 3 b , 1/2 dppe 3 c , PPh₃ 3 d , P(p‐Tol)₃ 3 e . All compounds are characterized by ¹H and ³¹P NMR spectra, for 3 b and 3 d also crystal structure determinations were performed. 3 b crystallizes in the triclinic space group P1 (No. 2) with a = 1212.58(7), b = 1430.74(8), c = 1629.34(11) pm, α = 77.321(6), β = 70.469(5), γ = 87.312(6)°. 3 d crystallizes in the triclinic space group P1 (No. 2) with a = 1122.60(9), b = 1355.88(11), c = 2025.11(14) pm, α = 83.824(9), β = 82.498(9), γ = 67.214(8)°.     

1‐Phosphabicyclo[2.2.1]heptane

1‐Phosphabicyclo[2.2.1]heptanes Exo‐endo‐ and exo‐exo‐2.6‐dimethyl‐1‐phosphabicyclo [2.2.1]heptane have been obtained by cyclization of 2‐methyl‐4‐(2‐propenyl)phospholane in the presence of the complex base, sodium salt of diethylenglycolmonoethylether ‐ sodium amide in THF (NAMEDEG). The bicyclic phosphanes are characterized by reac‐tions with selenium, sulfur, (CH₃)₂SeO, CH₃I and HSO₃F, respectively, elemental analysis, X‐ray crystal structure analysis as well as ¹H, ¹³C, ³¹P NMR spectral measurements. The steric demand of these phosphanes as complex ligands has been estimated from the P, H coupling constants of the phosphonium fluorosulphates according to the Tolman model. The phosphane selenides were found to display the lowest values for the ¹J(Se, P) coupling constant, found up to now for alicyclic and cyclic aliphatic tertiary phosphane selenides. The ⁿJ(P, H)‐ and ⁿJ(H, H)_{n=2, 3} coupling constants have been extracted from the proton spectra at 600 MHz by computerized analysis.     

Synthesis and Characterization of Organophosphazene Polyoxotungstate [（N3P3）（SiW11O39H2）3]^12-

A new organophosphazene polyoxotungstate, [(N3P3)(SiW11O39H2)3]^12-, has been prepared by reaction of hexachlorocyclotriphosphazene with undecatungstosilicate, and characterized by elemental analysis, infrared spectroscopy, and multinuclear ^31p NMR.     

配合物[Fe(CO)3(PPh2R)2(HgCl2)] (R=pym,fur, py,thi)的Fe-Hg相互作用及31P化学位移

In order to study the effects of R group on Fe-Hg interactions and 31P chemical shifts, the structures of mononuclear complexes Fe(CO)3(PPh2R)2 (R=pym: 1, fur: 2, py: 3, thi: 4; pym=pyrimidine, fur=furyl, py=pyridine, thi=thiazole) and binuclear complexes [Fe(CO)3(PPh2R)2(HgCl2)] (R=pym: 5, fur: 6, py: 7, thi: 8) were studied by using the density functional theory (DFT) PBE0 method. The 31P chemical shifts were calculated by PBE0-GIAO method. Nature bond orbital (NBO) analyseswere also performed to explain the nature of the Fe-Hg interactions. The conclusions can be drawn as follows: (1) The complexes with nitrogen donor atoms are more stable than those with O or S atoms. The more N atom there are, the higher is the stabilitity of the complex. (2) The Fe-Hg interactions play a dominant role in the stabilities of the complexes. In 5 or 6, there is a σ-bond between Fe and Hg atoms, However, in 7 and 8, the Fe-Hg interations act as σP-Fe→nHg and σC-Fe→nHg delocalization. (3) Through Fe邛Hg interactions, there is charge transfer from R groups towards the P, Fe, and Hg atoms, which increases the electron density on P nucleus in binuclear complexes. As a result, compared with their mononuclear complexes, the 31P chemical shifts in binuclear complexes show some reduction.     

Reaktionen von tBu2P–P=P(Me)tBu2 mit (Et3P)2NiCl2 und [{η2‐C2H4}Ni(PEt3)2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXIII. Reactions of ^tBu₂P–P=P(Me)^tBu₂ with (Et₃P)₂NiCl₂ and [{η²‐C₂H₄}Ni(PEt₃)₂] ^tBu₂P–P=P(Me)^tBu₂ ( 1 ) forms with (Et₃P)₂NiCl₂ ( 2 ) and Na(Nph) the [μ‐(1,3 : 2,3‐η‐^tBu₂P₄^tBu₂){Ni(PEt₃)Cl}₂] ( 3 ) as main product. Using Na/Hg instead as reducing agent the Ni⁰ compounds [{η²‐^tBu₂P–P}Ni(PEt₃)₂] ( 4 ), [{η²‐^tBu₂P–P=P–P^tBu₂}Ni(PEt₃)₂] ( 5 ) and [(Et₃P)Ni(μ‐P^tBu₂)]₂ ( 6 ) with four‐membered Ni₂P₂ ring result. [{η²‐C₂H₄}Ni(PEt₃)₂] yields with 1 also 4 . The compounds were characterized by ¹H and ³¹P{¹H} NMR investigations and 3 also by a single crystal X‐ray analysis. It crystallizes triclinic in the space group P 1 with a = 1129.4(2), b = 1256.8(3), c = 1569.5(3) pm, α = 72.44(3)°, β = 70.52(3)° and γ = 74.20(3)°.     

Applications of P NMR spectroscopy in development of M(Duphos)-catalyzed asymmetric synthesis of P-stereogenic phosphines (M = Pt or Pd)

This perspective describes the use of ³¹P NMR spectroscopy in an ongoing research project on enantioselective P−C bond formation catalyzed by platinum and palladium Duphos complexes. This technique was used to characterize catalyst precursors, intermediates and products, to determine equilibrium and rate constants, and to measure the enantiomeric excess (ee) of the P-stereogenic phosphine products. Applications of ³¹P NMR spectroscopy in problem-solving and identifying unexpected products, as well as the analysis of an unusual and esthetically pleasing spectrum, are also discussed.     

Quantum Chemistry Studies on the Fe-Cu Interactions and 31p NMR in Fe（CO）3（Ph2Ppy）2（CuXn） （Xn = Cl2^2-, Cl-, Br-）

In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, 4： Xn = Br-） are calculated by density functional theory （DFT） PBE0 method. For complexes 1, 3 and 4, the 31p NMR chemical shifts calculated by PBE0-GIAO method are in good agreement with experimental results. The 31p chemical shift is 82.10 ppm in the designed complex 2. The Fe-Cu interactions （including Fe→Cu and Fe←Cu charge transfer） mainly exhibit the indirect interactions. Moreover, the Fe-Cu（I） interactions （mostly acting as σFe-p→4Scu and aFe-C→4Scu charge transfer） in complexes 3 and 4 are stronger than Fe-Cu（Ⅱ） interactions （mostly acting as σFe-p→4Scu and σFe-p←4Sc,） in complex 2. In complex 2, the stronger Fe←Cu interac- tions, acting as σFe-p←44SCu charge transfer, increase the electron density on P nucleus, which causes the upfield 31p chemical shift compared with mononuclear complex 1. For 3 and 4, although a little deshielding for P nucleus is derived from the delocalization of σFe-p→4Scu due to the Fe→Cu interactions, the stronger σFe-c→np charge-transfer finally increases the electron density on P nucleus. As a result, an upfield 31p chemical shift is observed compared with 1. The stability follows the order of 2〉3=4, indicating that Fe（CO）3（PhzPpy）2（CuCl2） is stable and could be synthesized experimentally. The N-Cu（Ⅱ） interaction plays an important role in the stability of 2. Because the delocalization of σFe-p→4SCu and σFe-c→πc-o weakens the a bonds of Fe-C and ~r bonds of CO, it is favorable for increasing the catalytic activity of binuclear complexes. Complexes 3 and 4 are expected to show higher catalytic activity compared to 2.     

Komplexchemie P‐reicher Phosphane und Silylphosphane. XXV. Bildung und Struktur des [{cyclo‐P3(PtBu2)3}{Ni(CO)2}{Ni(CO)3}]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXV. Formation and Structure of [{ cyclo ‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}] ^tBu₂P–P=P(R)^tBu₂ (R = Br, Me) reacts with [Ni(CO)₄] yielding [{cyclo‐P₃(P^tBu₂)₃}{Ni(CO)₂}{Ni(CO)₃}]. The two cis‐^tBu₂P substituents of the cyclotriphosphane, which results from the trimerization of the phosphinophosphinidene ^tBu₂P–P, are coordinating to a Ni(CO)₂ unit forming a five‐membered P₄Ni chelate ring. The trans‐^tBu₂P group is linked to a Ni(CO)₃ unit. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with a = 933.30(5), b = 2353.2(1) and c = 3474.7(3) pm.     

Stereogenic properties of spiranes combined with one or two equivalent conventional centres of chirality

Derivatives of the tri-spirane pentaerythritoxy-cyclophosphazene compound 1 have been used to investigate the stereogenic properties of spiranes combined with either one or two conventional centres of chirality. In compound 1, the two inner rings are carbocyclic and symmetrical and the two outer rings are cyclotriphosphazenes substituted in different positions to provide the conventional centres of chirality. Reaction of 1 in a 1:1 molar ratio with the unsymmetrical dinucleophilic reagent, 1,3-aminopropanol, gave the mono-spiro substituted derivative 2, which was shown to exist as a racemate by X-ray crystallography and ³¹P NMR spectroscopy on addition of a chiral solvating agent (CSA). Reaction of 1 with 1,3-aminopropanol in a 1:2 molar ratio gave three diastereoisomeric di-mono-spiro products 3a-3c, which were all shown to be racemates using a combination of X-ray crystallography (3a, 3c) and ³¹P NMR spectroscopy on addition of a CSA (3b), thus proving the case of the stereogenic properties of spirane molecules combined with two equivalent conventional centres of chirality. It is also shown by quantitative ³¹P NMR spectroscopy of the reaction mixture and by isolation of reaction products that the proportions of the diastereoisomers 3a:3b:3c are in approximate ratios of 1:2:1, respectively, and these results have been rationalised by analysis of the stereogenic properties of the series of reactions 1 → 2 → 3.     

Chirality Recognition of Selenium Compounds by NMR Spectroscopy in the Presence of a Chiral Dirhodium Complex

Abstract

Diastereomeric adducts of chiral soft-base selenium ligands with the enantiopure dirhodium complex Rh* allows stereodifferentiation by NMR spectroscopy of various nuclei (dirhodium method). The individual adduct species can be identified by low-temperature NMR spectroscopy.     

[Co4P2(PtBu2)2(CO)8] und [{Co(CO)3}2P4tBu4] aus Co2(CO)8 und tBu2P–P=P(Me)tBu2

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XIX. [Co₄P₂(P^tBu₂)₂(CO)₈] and [{Co(CO)₃}₂P₄^tBu₄] from Co₂(CO)₈ and ^tBu₂P–P=P(Me)^tBu₂ Co₂(CO)₈ reacts with ^tBu₂P–P=P(Me)^tBu₂ yielding the compounds [Co₄P₂(P^tBu₂)₂(CO)₈] ( 1 ) and [{η^2tBu₂P=P–P=P^tBu₂}{Co(CO)₃}₂] ( 2 a ) cis, ( 2 b ) trans. In 1 , four Co and two P atoms form a tetragonal bipyramid, in which two adjacent Co atoms are μ₂‐bridged by ^tBu₂P groups. Additionally, two CO groups are linked to each Co atom. In 2 a and 2 b , each of the Co(CO)₃ units is η²‐coordinated to the terminal P₂ units resulting in the cis‐ and trans‐configurations 2 a and 2 b . 1 crystallizes in the orthorhombic space group Pnnm (No. 58) with a = 879,41(5), b = 1199,11(8), c = 1773,65(11) pm. 2 a crystallizes in the monoclinic space group P2₁/n (No. 14) with a = 875,97(5), b = 1625,36(11), c = 2117,86(12) pm, β = 91,714(7)°. 2 b crystallizes in the triclinic space group P 1 (No. 2) with a = 812,00(10), b = 843,40(10), c = 1179,3(2) pm, α = 100,92(2)°, β = 102,31(2)°, γ = 102,25(2)°.