Reactions of benzylchlorobis(triphenylphosphine)palladium(II) with dimethyl acetylenedicarboxylate

Benzylchlorobis(triphenylphosphine)palladium(II) reacted with dimethyl acetylenedicarboxylate to give [Pd[C(CO₂Me)=C(CH₂Ph)(CO₂Me)]Cl(PPh₃)₂] (II) and [(Ph₃P)ClPdμ-C(CO₂Me)=C(CO₂Me)PdCl(PPh₃) (III). Complexes II and III reacted with Tl(acac) to afford [PdC(CO₂Me=C(CH₂Ph)(CO₂Me)-(acac)(PPh₃)] and [(Ph₃P)(acac)Pdμ-C(CO₂Me)=C(CO₂Me)Pd(acac)(PPh₃)], respectively.     

Reactions of dimethyl acetylenedicarboxylate with hydridoalkynyl complexes of palladium(II) and platinum(II)

Reaction of trans-HM(PEt₃)₂ (CCC₆H₅) (M = Pt, Pd) with dimethyl acetylenedicarboxylate has given rans-{(CH₃O₂C)HC=C(CO₂CH₃)}M(PEt₃)₂ (CCC₆H₅). It is suggested that oligomerization of a terminal acetylene proceeds through an alkynylalkenyl derivative.     

Cyclopentadienyl- and pentamethylcyclopentadienyl-rhodium(III) complexes containing isocyanide ligands

The complexes [(η⁵-C₅H₅)RhCl₂]₂ and [(η⁵-C₅Me₅)RhCl₂]₂ react with stoichiometric amounts of isocyanide ligands L to give (η⁵-C₅H₅)RhLCl₂ and (η⁵-C₅Me₅)RhLCl₂ (L = CNC₆H₁₁, CNC₆H₄CH₃-p); an excess of ligand L reacts further with (η⁵-C₅Me₅)RhLCl₂ to give the cationic complex [(η⁵-C₅Me₅)RhL₂Cl]⁺ which was isolated as tetraphenylborate salt. The cationic complexes [(η⁵-C₅Me₅)RhL(PPh₃)Cl]⁺ and [(η⁵-C₅Me₅)Rh(Ph₂PC₂H₄PPh₂)Cl]⁺ were obtained in the reaction of (η⁵-C₅Me₅)RhLCl₂ with PPh₃ and Ph₂PC₂H₄PPh₂ respectively. Unidentified solids which do not contain the cyclopentadienyl moiety were obtained in the analogous reactions of (η⁵-C₅H₅)RhLCl₂ with an excess of isocyanide or of tertiary phosphine.The complexes (η⁵-C₅H₅)Rh(CNC₆H₁₁)Cl₂ and (η⁵-C₅Me₅)Rh(CNC₆H₁₁)Cl₂ react with SCN^? or SeCN^? giving the corresponding dithiocyanate or diselenocyanate derivatives in which the pseudohalogen groups are S- or Se-bonded to the metal atom. The analogous reactions with C₆Cl₅MgCl gave the chiral complexes (η⁵-C₅H₅)Rh(CNC₆H₁₁)(C₆Cl₅)Cl and (η⁵-C₅Me₅)Rh(CNC₆H₁₁)(C₆Cl₅)Cl.The potentially chelating anion Ph₂PSS^? reacts with (η⁵-C₅H₅)Rh(CNC₆H_n11)Cl₂ and (η⁵-C₅Me₅)Rh(CNC₆H₁₁)Cl₂ to give (η⁵-C₅H₅)Rh(CNC₆H¹¹)(SSPPh₃)Cl and (η⁵-C₅Me₅)Rh(CNC₆H¹¹)(SSPPh₂)Cl in which the dithio ligand acts as monodentate; these compounds react with MeI or EtI to give the dihalide derivatives and the esters Ph₂PSSMe and PSSEt. The complex [(η⁵-C₅Me₅)Rh(CNC₆H₁₁)(SSPPh₂)]Cl was obtained by refluxing a benzene solution of the corresponding neutral complex; the cyclopentadienyl derivative failed to give the analogous chelate complex.The complexes (η⁵-C₅H₅)RhLCl₂, (η⁵-C₅Me₅)RhLCl₂ and [(η⁵-C₅Me₅)RhL₂Cl]⁺ (L = CNC₆H₁₁) were found to be unreactive towards amines.     

Reactions of tetrakis(dimethylamino)ethylene with weak acids

Tetrakis(dimethylamino)ethylene reacts in methanol at 25° to give carbon-carbon bond cleavage, substitution of methoxyl for dimethylamino and addition of methanol to the double bond. The principal products are dimethylamine, dimethoxydimethylaminomethane and 1,1,2-trimethoxy-1,2-bis(dimethylamino)ethane. Minor products are methoxydimethylamino-N,N-dimethylacetamide, trimethylamine and dimethyl ether. An oxidation-reduction side reaction forms a very small amount of the radical cation of tetrakis(dimethylamino)ethylene. In the presence of sodium methoxide no carbon-carbon bond cleavage occurs and no radical cation is formed. When methanol is dissolved in tetrakis(dimethylamino)ethylene (methanol 1M), the principal products are 1,1,2-trimethoxy-1,2-bis(dimethylamino)ethane and dimethylamine with small amounts of tris(dimethylamino)methoxyethylene and 1,2-bis(dimethyl amino)-1,2-dimethoxyethylene. Tetrakis(dimethylamino)ethylene and water give dimethylamine and dimethylformamide.     

Reactions of dimethyl 2-methoxyisoxazolidine-3,3-dicarboxylate catalyzed by Lewis acids

Evidence is presented for a synchronous mechanism of the acid-catalyzed 1,2-rearrangement of 2-methoxy-isoxazolidine-2,3-dicarboxylic acid ester with migration of the ester group to the N atom. It was shown that the reaction is suppressed in the presence of an external nucleophile or a reducing agent. The regularities found were used to explain the transformations of bicyclic systems with an -ONO-fragment.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 114–121, January, 1991.     

Reactions of simple phospholes with dimethyl acetylenediearboxylate

Reactions of the three phospholes 1-phenylphosphole, 3-methyl-1-phenylphosphole and 3,4-dimethyl-1-phenylphosphole with dimethyl acetylenedicarboxylate are reported. All three phospholes react extremely readily with the acetylenic ester to give ring-expanded bicyclic ylidic systems, although 1-phenylphosphole appears to react by a different pathway from the other two phospholes. These reactions show that simple phospholes in general, in contrast to heavily substituted phospholes, are quite good nucleophiles in organic reactions and the results of this study are consistent with a relatively easily perturbed aromatic structure for these phospholes.     

Reactions of N-carbethoxymethylamides of dialkylthio(seleno)phosphoric acids with paraform

Conclusions A number of methylenebis-[N-dialkoxythio(seleno)phosphoryl-N-carbethoxymethylamines] was obtained by the condensation of the N-carbethoxymethylamides of dialkylthio(seleno)phosphoric acids with paraform,Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2603–2604, November, 1974.     

Reactions of iridium bis(phosphinite) pincer complexes with protic acids

Iridium pincer complexes [C₆H₃-2,6-(OPBu^t ₂)₂]Ir(H)Cl (10) and [4-EtOOCC₆H₂-2,6-(OPBu^t ₂)₂]Ir(H)Cl (11) react with protic acids undergoing metallation of one of the tert-butyl groups to form double cyclometallated products [4-R-C₆H₂-2-(OPBu^t ₂)-6-(OP(Bu^t)CMe₂CH₂)]IrCl (12, R = H; 13, R = COOEt), which are stable in air. Complex 12 reacts with CO and Bu^tNC giving the corresponding 18-electron complexes [C₆H₃-2-(OP-Bu^t ₂)-6-(OP(Bu^t)CMe₂CH₂)]Ir(L)Cl (14, L = CO; 15, L = CNBu^t). The structure of compound 14 was established by X-ray diffraction analysis.     

Copper (I) complexes with some disubstituted acetylenes and dimethylsulphoxide

Twelve copper (I) cyanide, bromide and chloride complexes with disubstituted acetylenes (RR¹C(OH)CCX; R, R¹ = CH₃ or C₂H₅, X = Br, CN or Cl) and dimethylsulphoxide (DMSO) were prepared and characterized. In all cases, the molar ratio of copper to dimethylsulphoxide and disubstituted acetylene was 4:2:1. The ¹H NMR, u.v. absorption and i.r. spectra (4000-600 cm⁻¹) of the copper (I) complexes were measured. The elemental analysis and spectral data suggest that the disubstituted acetylene is coordinated to the copper (I) atom via the π-bond using two-electron, three-centre carbon—metal bonds.     

Reactions of dimethoxycarbene with dimethyl 2,3-dicycanomaleate and fumarate

Dimethoxycarbene, in 2-fold or larger excess, reacts with dimethyl 2,3-dicyanomaleate and fumarate to afford an unstable dihydrofuran 1:1 adduct that was shown to react further with the carbene to afford a 2:1 adduct reported previously. In an astonishing process, the dihydrofuran reacts with water to afford a mixture of (d,l and meso) dimethyl 2,3-dicyanosuccinates in which both hydrogen atoms of water were used to hydrogenate a C=C bond.     

Reactions of diols with dimethyl carbonate in the presence of W(CO)6 and Co2(CO)8

Dimethoxyalkanes and dimethyl alkanediyl biscarbonates were synthesized by reactions of diols with dimethyl carbonate in the presence of tungsten and cobalt carbonyls. Optimal reactant and catalyst ratios and reaction conditions were found to ensure selective formation of dimethoxyalkanes or dimethyl alkanediyl biscarbonates.     

Thermal analysis of new dimethyl/dibutyl tin(IV) compounds with amino acids

Six diorganotin(IV) compounds with amino acids of general formula [(CH₃)₂SnAACl]₂ and [(CH₃CH₂CH₂CH₂)₂SnAACl]₂ (where AA = l-methioninate, l-cysteinate, and l-tryptophanate) were synthesized by reacting dimethyltin(IV) dichloride (M) and dibutyltin(IV) dichloride (B) with l-methionine (M₁) or l-cysteine (C) or l-tryptophan (T) using acetonitrile as solvent and designated as MM₁, MC, MT, BM₁, BC, and BT. The structural characterization of dimethyltin(IV) and dibutyltin(IV) compounds were done using elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR, and ¹¹⁹Sn-NMR spectroscopy. The thermal properties of the synthesized compounds were studied by thermogravimetric analysis and differential scanning calorimetry techniques in a dynamic atmosphere of nitrogen. The thermal decomposition mechanisms were similar for compounds MM₁, BM₁, MC, BC, and occurred in one step, while in compounds MT and BT it occurred in two consecutive steps. The TG curves of the MT and BT compounds suggest the loss of the ligand (AA) in the first step, with probable formation of a tin oxide R₂SnO intermediate. At the end of the second step free tin is obtained similar to the MM₁, BM₁, MC, BC in accordance with the stoichiometry of the related compounds.     

Reactions of mercapto amino acids Communication 7. Reactions of N-acyl-2,3-dihaloalanines, (acyloxy)pyruvic acids

Russian Chemical Bulletin -     

Tetrachloro (NN-dimethylformamide) (dimethylsulphoxide) TIN (IV) revisited

The previously reported mixed ligand compound SnCl₄ (DMF) (DMSO) (DMF=NN-Dimethylformamide, DMSO=Dimethylsulphoxide) has been studied by IR, Raman and Mössbauer spectroscopy. Our results confirm its homogeneity with the DMF and DMSO ligands coordinating in cis position through the oxygen atoms. The compound does not isomerize when heated to 135 C, but decomposes giving rise to cis-SnCl₄(DMSO)₂ and trans-SnCl₄ (DMF)₂.     

Reactions of N-substituted 2,6(3,5)-dialkyl-1,4-benzoquinone imines with arenesulfinic acids

The regioselectivity in the reactions of N-arylsulfonyl-2,6-dialkyl-1,4-benzoquinone imines with arenesulfinic acids (1,6-, 6,1-, or 6,3-addition) is determined by steric factor, while in the reactions of N-aroyl-1,4-benzoquinone imines electronic effect of substituents in the quinoid ring is crucial. The reactions of N-arylsulfonyl-3,5-dimethyl-1,4-benzoquinone imines with arenesulfinic acids follow mainly the 1,4-addition pattern. N-(N-Arylsulfonylbenzimidoyl)-1,4-benzoquinone imines are capable of reacting in a way similar to both N-arylsulfonyl and N-aroyl derivatives.     

Dimethylformamide and dimethylsulphoxide adducts of tin(II) perchlorates

The synthesis and some properties of dimethylformamide and dimethylsulphoxide adducts of tin(II) perchlorates are described. Coordination is discussed from molar conductance measurements, infrared and nmr spectra.     

Reactions of N-sulfinyltrifluoromethanesulfonamide with carboxylic acids

Phenylacetic, diphenylacetic, salicylic, and cinnamic acids reacted with N-sulfinyltrifluoromethanesulfonamide (CF₃SO₂NSO) to give the corresponding N-acyltrifluoromethanesulfonamides CF₃SO₂NHCOR (R = PhCH₂, Ph₂CH, o-HOC₆H₄, PhCH=CH). The reaction of N-sulfinyl-trifluoromethanesulfonamide with 3-hydrazinobenzoic acid occurred at the hydrazino group of the latter with conservation of the carboxy group and without elimination of SO₂, and the product was 3-(2-sulfinylhydrazino)benzoic acid OSNNHC₆H₄CO₂H.