SYNTHESIS AND CONFORMATIONAL STUDIES OF A NUMBER OF SATURATED BICYCLIC SIX-MEMBERED RING PHOSPHITES

Abstract

An ¹H NMR study of the conformation of the dioxaphosphorinane ring of a number of diastereoisomeric bicyclic saturated six-membered ring phosphites (3ab-10ab) has been performed. The dioxaphosphorinane ring of these phosphites is transannelated with a tetrahydrofuran, cyclopen-tane, tetrahydropyran or cyclohexane ring. The substituent on the phosphorus atom is a methoxy or phenoxy group. It is shown that the cis isomers 3a-10a prefer a chair conformation of the dioxaphosphorinane ring, independent of the substituent on the phosphorus atom and of the nature of the transannelated ring. In contrast, for the trans isomers 3b-10b a twist rather than a chair conformation of the dioxaphosphorinane ring is preferred. The fraction of the twist conformer in the trans isomers is mainly determined by the substituent on phosphorus. The size and composition of the transannelated ring are relatively unimportant in this respect. For both cis and trans isomers the preferred geometry is solvent-independent. The measured ^3JPOCH couplings of the cis isomers 3a-10a are used to formulate an expression for the dependence of such couplings upon dihedral angles in bicyclic phosphites.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF Ru3(CO)9(PPh3)3

Abstract

The synthesis of tertiary phosphine and phosphite substituted derivatives of M₃(CO)₁₂ {M = Ru(1a) Os(1b)} is discussed and the X-ray crystal and molecular structure of the tris-triphenylphosphine substituted ruthenium cluster Ru₃(CO)₉(PPh₃)₃ (2a) is reported. Complex 2a crystallises in the monoclinic space group P2₁/n with cell parameters a = 14.180(9), b = 21.644(14), c = 18.248(10) Å, β = 92.52(5)°, V = 5595(6) Å ³, Z = 4. The structure was solved by full-matrix least-squares methods based on F ². The refinement converged at R1 = 0.0564, wR2 = 0.2125 for 4857 observed data [F > 4σ(F)].     

SYNTHESIS AND REACTIONS OF HALO DERIVATIVES OF 4-ISOPROPYL-2H-1,4-THIAZIN-3-ONE

Abstract

Reaction of 4-isopropyl-2H-1,4-thiazin-3-one 1 (R [dbnd] i-Pr) with N-chloro- and N-bromosuccinimide occurred exclusively at the 6-position to give 6-chloro and 6-bromo derivatives of 1 (R [dbnd] i-Pr), respectively, in high yield, in sharp contrast to the 2-aroyloxylation by benzoyl peroxide or m-chloroperbenzoic acid reported earlier.² Reaction of 1 (R [dbnd] i-Pr) with methanesulfonyl chloride in the presence of aluminum chloride afforded an addition compound, 4-isopropyl-5,6-dichloro-1,4-tetrahydrothiazin-3-one. The 2-chloro derivative 6 of 1 (R [dbnd] i-Pr) was successfully prepared by hydrolysis of the 2-m-chloroben-zoyloxy derivative of 1 (R [dbnd] i-Pr) followed by treatment with thionyl chloride. Derivative 6 reacted readily under mild conditions with water, alcohols, thiols, ammonia and amines to give various 2-substituted compounds of 1 (R [dbnd] i-Pr). With phenol as a nucleophile, 1 (R [dbnd] i-Pr) reacted exclusively at the para position. Reaction at carbon atoms also occurred with N,N-dimethylaniline and 2,6-xylidine.     

VIBRATIONAL SPECTRA AND STRUCTURE OF ALKOXY AND CHLOROALKOXY DERIVATIVES OF ANTIMONY(V)

Abstract

Vibrational spectra of (CH₃O) _n SbCl_5–n . n = 1: 1; n = 2: 2: n = 3: 3: n = 4: 4; n = 5: 5; have been recorded. According to ir and Raman data 1–5 are centrosymmetrical bridged dimers. The Raman spectra of 3–5 exhibit v(Sb–O) doublets of terminal CH₃O at 530–541 and 550–570 cm^?1; vibrations of the 4-membered Sb₂O₂ ring, observed in the 500–517 cm^?1 region of the ir spectra of 1–5, are absent. The v(C–O) bands of bridged and terminal CH₃O are shifted to higher wave numbers (60 and 31 cm^?1, respectively) in the series 1 → 5. The stability of the dimers increases in the series 1 < 2 < 3 < 4 ? 5. At 100–120°C and in CH₃CN solutions dimers of 1–3 dissociate to monomers (v(Sb–O) 537–540 cm^?1, ir data). The monochloride, 4, is partially dissociated in CH₃CN. On solution of the tetrachloride, 1, in benzene a dimer-monomer equilibrium has been observed, with the dimeric form being predominant.     

ALKATRIENYL SULFOXIDES AND SULFONES. PART IV. SYNTHESIS AND ELECTROPHILEINDUCED CYCLIZATION REACTIONS OF 3-METHYL-1-METHYLSULFONYLPENTA-1,2,4-TRIENE

A method for synthesis of 3-methyl-1-methylsulfonylpenta-1,2,4-triene (3) by [2,3] sigmatropic rearrangement of 3-methylpent-1-en-4-yn-3-yl methanesulfinate (2), formed in the reaction of 3-methylpent-1-en-4-yn-3-ol (1) with methylsulfinyl chloride has been found. Electrophile-induced reactions of the vinylallenyl sulfone (3) occur in different pathways depending on the used electrophiles. The halogenation leads to the formation of (1E)-2-halo-3-methylene-1-methylsulfonylpenta-1,4-dienes (4) and (5). Reactions with phenylsulfenyl and phenylselenenyl chlorides afford only heterocyclic products, 3-methyl-2-[methylsulfonylmethyl]thiophene (6) in the case of sulfenyl chloride, and a mixture of 2,5-dihydroselenophene (7) and selenophene (8) in the case of selenenyl chloride.     

Interaction of Tris(3-Hydroxymethyl)Phosphine with Cinnamic Acids

Abstract

Phosphonium zwitterions of the known type R₃P⁺CH(Ar)CH₂CO₂ ^? (II) are obtained as a racemic mixture in moderate yield via a 1:1 reaction of cinnamic acids (Ar = phenyl, or substituted phenyl) with [HO(CH₂)₃]₃P in acetone at room temperature under Ar. The products are characterized by elemental analysis, ³¹P{¹H}-, ¹H-, and ¹³C{¹H}-NMR spectroscopies, and mass spectrometry, although they contain a minor coproduct formed via neutralization of the positive and negative charges of II with the respective acid and phosphine reactants (see Experimental Section). In CD₃OD, the monodeuterated salts R₃P⁺CH(Ar)CH(D)CO₂ ^? are formed as a mixture of diastereomers with d.r. values of ～2 to 8, depending on substituent groups present in the organic acid; in these studies, 2-HO-cinnamic acid is the most reactive, and β-methylcinnamic acid is the least reactive.     

REACTION OF 5,5-DIPHENYL-2-THIOHYDANTOIN WITH 1,4-DIBROMOBUTANE. THE CRYSTAL AND MOLECULAR STRUCTURE OF 2,3,4,5-TETRAHYDRO-7,7-DIPHENYLIMIDAZO-[2,1-b]-THIAZEPINE-8(7H)-ONE

Abstract

The reaction of 5,5-diphenyl-2-thiohydantoin (1) (DPTH) or its potassium salt (DPTH-K) with 1,4-dibromobutane gave two isomeric bicyclic products: 2,3,4,5-tetrahydro-7,7-diphenylimidazo-[2,1-b]-thiazepine-8(7H)-one (6) and 2,3,4,5-tetrahydro-8,8-diphenylimidazo-[2,1-b]-thiazepine-7(8)-one (7) in different ratios depending on the reaction conditions: [DPTH-K, EtOH, N-ethylpiperdine; phase transfer catalytical conditions: DPTH-K, Et₃N, benzene/water or DPTH acetone/K₂CO₃]. Compound (6) crystallizes in the space group P2₁/c with a = 10.4624(2), b = 8.3643(1), c = 18.4371(3) Å β = 96.3(1)°. The 7-membered thiazepine ring in (6) adopts a disordered chain conformation. The discussion of some physico-chemical properties and some factors showing the influence on the yield and ratios of isomeric compounds [(2), (3)], [(4), (5)] and [(6), (7)], obtained in the alkylation of DTPH (1) with dibromoalkanes, has been carried out.     

SYNTHESIS AND PHOTOPHYSICAL PROPERTIES OF POLYMER-BOUND HEXANUCLEAR MOLYBDENUM CLUSTERS

Abstract

The coordination of [Mo₆Cl₈ ⁱ(SO₃CF₃)₆ ^a]^2? (1) and [Mo₆Cl₈ ⁱCl₄ ^a(EtOH)₂ ^a] (2) to poly(evinylpyridine) (PVP) produces crosslinked materials. Formation of these materials occurs by displacement of axial ligands ((a) in Fig. 1) SO₃CF₃ ^? or EtOH on the clusters by the vinylpyridine moieties. The availability of six coordination sites in 1 and two coordination sites in 2 offers control over the degree of crosslinking and solubility of the materials. Similarly, varying the ratio of cluster coordination sites (C) to polymer-pendant pyridine ligands (P) yields materials with a wide range of solubilities and glass transition temperatures (T_g). Materials with C:P ratios of 1:100 are highly soluble in CH₂Cl₂ and MeOH, with T_g values slightly higher than that of pure PVP. Unswellable materials with no discernible T_g are obtained with C:P ratios of 1:5 and lower, indicating a high degree of crosslinks. Transient emission spectroscopy reveals that polymer-bound cluster 1 lacks the luminescent properties characteristic of many [Mo₆Cl₈]⁴⁺ based clusters. Conversely, polymer-bound cluster 2 displays intense luminescence and retains the unusually long-lived excited-state observed for the free clusters in solution. The emission lifetime of PVP-bound 2 fits a biexponential decay, with τl₁ = 90 μs (60 %) and τ₂ = 8 μs (40 %), while [Mo₆Cl₈ ⁱCl₆ ^a]^2? has a uniexponential decay of τ = 156 μs in CH₂Cl₂ solution.     

SYNTHESIS AND STRUCTURES OF DICHLOROTETRAKIS-(PHENYLTHIOUREA) CADMIUM(II) AND CATENA-BIS(THIOCYANATE) BIS(PHENYLTHIOUREA)CADMIUM(II)

Abstract

Two new cadmium(II) complexes with phenylthiourea (PTU), namely Cd(PTU)₄Cl₂ (1) and [Cd₂(NCS)₂(μ₂-SCN)₂(PTU)₂(μ₂-PTU)₂] _n (2), have been prepared and characterized structurally by X-ray diffaction. Complex 1 crystallizes in the monoclinic space group C2/c, with a = 27.057(13), b = 8.108(3), c = 16.751(8) Å, β = 114.46°, V = 3345(3) ų, Z = 4. Complex 2 crystallizes in the triclinic space group P-1, with a = 9.336(3), b = 14.686(5), c = 16.911(5) Å, α = 71.36(2), β = 84.31(2), γ = 72.470(10)°, V = 2095.0(12) ų Z = 4. The structural analysis shows that each metal atom in both the mononuclear complex 1 and polynuclear complex 2 is octahedrally coordinated by four sulfur atoms and two chloro ligands or two nitrogen atoms from the thiocyanate groups, respectively. The PTU ligand can serve as either a monodentate ligand or a μ₂-bridging ligand upon coordination to a metal atom.     

SYNTHESES,STRUCTURES AND REACTIONS OF NEW AND NOVEL FOUR-, FIVEAND SIX-MEMBERED UNSATURATED N,P-HETEROCYCLE COMPLEXES

Metal-assisted heterocyclic ligand syntheses are reported using 2-H-azaphosphirene complex 1 or 7-phosphanorbornadiene complex 7 as starting material. Thermal decomposition of complex 1 led to 1,2dihydro-1,2,3-azadiphosphete complex 2, which was transformed into 2,6-dihydro-1,3,2,6-diazadiphosphinines 5a, b via ring expansion with carbonitriles 3a, b. Insertion of tert-butyl isonitrile into the P─ P bond of 2 at ambient temperature furnished the first Δ ¹ -1,3,5-azadi-phospholene complex 6─P bond of 2 using 7 failed. The 1,2,3,4-azatriphospholene complexes 9a, b were obtained by thermolysis of complex 2 in the presence of functionalized carbonitriles 8a, b.     

3-Aminoacetylthiazolidine-4-carboxylate esters and their l-thia-4-azaspiro[4.5]decane-3-carboxylate derivatives. Synthesis and stereochemical properties

Dimethyl thiazolidine-2,4-dicarboxylate 2 and ethyl l-thia-4-azaspiro[4.5]decane-3-carboxylates 3-5 were obtained as a diastereoisomeric mixture while their 3-aminoacetyl derivatives were isolated in only one isomeric form. These reactions of N-acylation were stereoselective, which can be explained by an interconversion of the diastereoisomers via a seco intermediate. The ¹H nmr analysis of amides 6 and 11 exhibited the presence of both cis and trans amide bond conformations, whereas only one cis conformation was observed for spiro amides 8-10 and 13-15.     

SYNTHESIS AND REACTVITY OF N-[N-PHOSPHORAMIDO-1H-BENZIMIDAZOL-2-YL] IMIDATES

N-(-1H-Benzimidazol-2-yl) imidates 1a–c react with chlorophosphoramide to give the N-[-1-N,N,N′,N′-tetramethylphosphoramidoyl-1H-benzimidazol-2-yl]-imidates 2a–c or with dichlorophosphoramide to yield the bis[(N-1-benzimidazol-2-yl)-imidate] phosphoramide derivatives 3a–b. The reaction of compounds 2a–c toward primary amines is studied. The obtained amidine derivatives 4a–b were unambiguously characterized by different spectroscopic techniques (IR, ¹H, ¹³C, and ³¹P NMR, and in some cases MS).     

Thermische Umlagerungen von (+)-Isopinocampheol und (−)-Isopinocamphon

Short-path thermolysis of (+)-isopinocampheol ( 1 ) at about 330° in the gas phase yields mainly (—)-(3 S, 4 S)-3, 7-dimethyl-octa-1,6-dien-4-ol ( 2 ). Longer heating of 2 at about 290–330° yields as main products the diastereoisomeric hydroxy-Δ⁸-iridenes 3, 4 and 5 in ratios dependent on temperature. Above 400°, formation of 4-methylpent-3-en-1-al ( 7 ) and 2-butene ( 8 ) predominates. Compounds 7 and 8 also appear as the stable final thermolysis products of 3, 4 and 5 above 500°. Small quantities of (+)-iso-dihydrocarveol ( 6 ) always occur as by-product in the thermolysis of 1 . Short-path thermolysis of (—)-isopinocamphone ( 13 ) at about 430° leads, with slight epimerisation, to the three diastereoisomeric oxo-Δ⁸-iridenes 15, 18 and 17 via (+)-(3 S)-3, 7-dimethylocta-1, 6-dien-4-one ( 14 ). Structure and stereochemistry of all reaction products are established spectroscopically and chemically.     

SYNTHESIS OF METAL- AND PENTEL-CONTAINING HETEROCYCLES USING NITRILES AND ISONITRILES

The reaction of benzylnitrile with InMe ₃ in a molar ratio of 3:1 leads to 2-amino-N-[Me ₂ In(TMEDA)]-4-amino-3,5-diphenyl-6-benzyl-pyridine 2. CsF accelerates the reaction. The treatment of Ph ₂ CHCN with InMe ₃ in the presence of CsF gives the metalated ketenimine [(THF)Me ₂ InNCCPh ₂ ] ₂ 3. 3 and the corresponding Ga compound also can be obtained by the metathesis reaction of Me ₂ MCl with LiNu═C═CPh ₂ . The attack of the Lewis bases ^t BuELi ₂ (E = P, As) on nitriles and isonitriles also leads to oligomerizations. ^t BuAsLi ₂ reacts with two molecules of PhCN to the aromatic heterocycle [AsNC(Ph)NC(Ph)]^? by forming the salt [Li(diglyme) ₂ ] [(TMEDA)Li([AsNC(Ph)NC(Ph)]) ₂ ] 4, while the reaction of ^t BuAsLi ₂ with three equivalents of ^c HexNC leads to the dilithium compound [{Li ₂ (diglyme)} ₂ { ^t BuAs(CN ^c Hex) ₃ } ₂ ] 5. Six molecules ^c HexNC were consumed when Li ₂ P ^t Bu was added to the isonitrile to give [{Li(DME)} ₂ { ^t BuP(CN ^c Hex) ₅ (CH)}] 6.     

HYDROXYALKANESULFONYL CHLORIDES FROM CHLORINATION OF HYDROXYALKANESULFINATE SALTS IN A NONPOLAR MEDIUM: 3-HYDROXY-1-PROPANESULFONYL AND 4-HYDROXY-1-BUTANESULFONYL CHLORIDES

Abstract

3-Hydroxy-1-propanesulfonyl chloride (1b) was obtained for the first time (admixed with 10% of propane sultone, 2b) by chlorination of a dichloromethane suspension of sodium 3-hydroxy-1-propanesulfinate (3b). 4-Hydroxy-1-butanesulfonyl chloride (1c) containing 13% butane sultone (2c) was prepared similarly from 3c. The cyclizations of 1b and 1c in CDCl₃ containing 1-butanol (0.9 M) showed first order rate constants of 1.4 × 10^?4 and 6.4 × 10^?5 s^?1, corresponding to effective concentrations of 4.5 × 10² and 2.1 × 10² M, respectively. Reaction of triethylamine in ethanol-d (a) with 1b gave exclusively the undeuterated sultone (2b), evidently by a direct cyclization, and (b) with 1c produced mainly ethyl 4-hydroxy-1-butanesulfonate largely monodeuterated at the α-position, and presumably formed by way of the sulfene (6c).     

31P NMR NON-EQUIVALENCE OF THE DIASTEREOISOMERIC PHOSPHONODIDEPSIPEPTIDES. PART II1

Abstract

³¹P chemical shifts are reported for 24 different models of diastereoisomeric phosphonodidepsipeptides coupled from the N-protected L-aminoacids and dibenzyl esters of chiral 1-hydroxyalkylphosphonic acids. The ³¹P NMR nonequivalence variations with the changing of didepsipeptide structure, solvent and temperature were investigated. Amide cis-trans isomerism were observed in the case of Z-L-proline derived didepsipeptides.     

STEREOCHEMICAL PROPERTIES OF THE 1-CHLORO-1- PHENYL-2,5-DIMETHYL-2-PHOSPHOLENIUM ION AND DERIVED OXIDE AND PHOSPHINE

Abstract

The cycloaddition of phenylphosphonous dichloride and trans, trans-2,4-hexadiene, or the addition of chlorine to trans-1-phenyl-cis-2,5-dimethyl-3-phospholene, gave 1-chloro-1-phenyl-2,5-dimethyl-2-phospholenium chloride. This compound shows no evidence in its ³¹P and ¹H nmr spectra for the existence of cis, trans isomers, yet on hydrolysis or dehalogenation with magnesium the resulting oxide and phosphine, respectively, are seen to be isomer mixtures. This phenomenon is explained by a rapid equilibration of the cis, trans form of the I-chloro ion through a pentacovalent species. Structures of the oxides and phosphines were assigned by ¹H and ¹³C nmr relations. The 1-phenyl-cis-2,5-dimethyl-3-phospholenium ion and related compounds were also characterized.     

SYNTHESIS AND COMPLEXATION OF A NOVEL SOLUBLE VIC-DIOXIME

Abstract

A new soluble vic-dioxime, l,4-bis(2-methoxyethyl-2, 3-bis(hydroxyimino)-5, 6-diphenylpiper-azine (LH₂) has been synthesized as a mixture of isomers from dicyan di-N-oxide and 1, 2-diphe-nyl-l,2-bis(2′-methoxyethylamino)ethane, 1, which has been prepared through the reduction of the condensation product of benzaldehyde and 2-methoxyethylamine with the aluminium amalgam. LH₂ gives N,N-coordinated planar metal complexes with Co^II, Ni^II, Cu^II and Pd^II Oxidation of (LH)₂Co in the presence of a base such as py or triphenylphoshine leads to octahedral complexes (LH)₂Co(B)Cl. The uranyl complex of LH₂ has a 1 :1 metal-ligand ratio and a binuclear structure with μ-hydroxo bridges.     

SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF THE CHLORIDE-BRIDGED FACE-SHARING BIOCTAHEDRAL DIRHODIUM COMPLEX [HP-i-Pr3][Rh2Cl7(P-i-Pr3)2]

Abstract

The reaction of an ethanolic suspension of [NH₄]₃RhCl₆] and P-i′-Pr₃, in the presence of concentrated HC1, for 24h, gives [HP-i-Pr₃][Rh₂Cl₇(P-i-Pr₃)₂], 1, in 18.5% yeild and a small amount of Rh(H)(Cl)₂(P-i-Pr₃)₂, 2. The dinuclear complex 1 was characterized by elemental analyses, IR, ¹H, ³¹P NMR spectroscopy, and single crystal X-ray analysis. However, when the above reaction is continued for 48 h one obtains only 2, in good yield. It is proposed that complex 1 is a reaction intermediate leading to 2. Crystallographic data for 1 (at 298 K) are a = 15.944(3), b = 22.413(4), c= 11.500(4) Å, space group Pna2_x (Z = 4).     

SYNTHESIS OF THE FIRST BENZODISELENAGERMOLES AND ONE SPIROBISDISELENAGERMOLE

Abstract

The first examples of compounds R¹R²GeSe₂C₆H₄R³ (R¹,R²=CH³ C₂H₅, C₃H₂, n-C₄H₉, i-C₅H₁₁, Ph, p-CH₃Ph. R³=H, CH₃, OCH₃) were easily obtained (40–80% yield) from electrophilic cleavage of diselenophenylene zirconocenes by dialkyl or diaryl dichlorogermanes. The synthesis of a spirodi-selenagermole was achieved in the same way using germanium tetrachloride. Analytical data, ¹H and ⁷⁷Se NMR. mass spectra are perfectly consistent with the expected structures.