Reactions of group IV organometallic compounds : XXIX. Insertion reactions of (trimethylsilylmethylene)phosphorane with heterocumulenes. Inhibition of Wittig type reactions

A reaction of (trimethylsilylmethylene)dimethylphenylphosphorane, PhMe₂PCHSiMe₃ (I), with phenyl isocyanate affords a 2/1 insertion product, which results from insertion of phenyl isocyanate into both the CSi and CH bonds of I. By way of contrast, a reaction of isothiocyanate and carbon disulfide with I affords 1/1 products by insertion of these heterocumulenes into the CSi bond of I. In these reactions, Wittig-type elimination of dimethylphenylphosphine oxide or sulfide did not occur because of irreversible migrations of the trimethylsilyl group to the anionic centers of the Zwitterionic intermediates.     

Reaction of ketenes and phenyl isocyanate (and its S-containing analogs) with the complexes of metals of the platinum group

Conclusions We obtained the complexes of (Ph₃P)₃PtO₂ with diphenylketene, phenyl isocyanate, carbon suboxide. PhNCS and PhNSO, and also the complex: (Ph₃P)₂RhCl·2PhNCO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1181–1183, May, 1972.     

Convenient synthesis of (triphenyl)germyl and (triphenydstannyl substituted allenes

Allenyl-germanes and -stannanes, Ph₃MC(R)CCR′R″ (M = Ge, Sn) can be obtained, generally in excellent yield, through alkylcopper(I)-induced 1,3-substitution of the propargylic chlorides Ph₃MCCCR′R″Cl. In the tin series, however transmetallation is the main process when MeCu, H₂CCHCu or PhCu are used. The allenyl compounds in which R is (trimethylsilyl)ethynyl or 4,4-dimethyl-1,2-pentadienyl can be obtained by using the organozinc compounds instead of the copper(I) compound and using tetrakis(triphenylphosphine)palladium as catalyst.     

1,3-Bis(triphenylphosphonium-ylidyl)cyclotetraphosphane

1,3-Bis(triphenylphosphonium-ylidyl)cyclotetraphosphines The title compounds 3a , b result from the condensation of the ylidyldichlorophosphines Ph₃PCR? PCl₂ 1a , b (R = Me, 3-Tol) with phenyl bis(trimethylsilyl)phosphine 2 . Analysis of the ³¹P-NMR spectra and the X-ray structure investigation of 3a demonstrate a folding of the four-membered ring and an all-trans orientation of the substituents.     

Acyl- und Alkylidenphosphane. XXVI. 2, 4-Bis(phenylimino)-1,3-diphosphetane aus Thiocarbamoyl- und Carbamoyltrimethylsilylphosphanen

Acyl-and Alkylidenephosphines. XXVI. 2, 4-Bis (phenylimino)-1, 3-diphosphetanes from Thiocarbamoyl- and Carbamoyltrimethylsilylphosphines . Bis(trimethylsilyl)phosphines R? P[? Si(CH₃)₃]₂ 1 (R = H₃C a, H₅C₆ b, (H₃C)₃C e, H₁₁C₉ d) and phenyl isothiocyanate give insertion compounds which were identified as [CN-phenyl, N-trimethylsilyl)thiocarbamoyl]trimethylsilylphosphines 3 ? 2 in solution as well as in the solid state [2]. In the presence of small amounts of solid sodium hydroxide the phenyl derivative 3 ? 2b eliminates bis(trimethylsilyl) sulfane, whereas the tert-butyl 3 ? 2c and the mesityl compound 3 ? 2d show the same reaction even without a catalyst. The unstable [(phenylimino)methylidene]phosphines 6 formed first, dimerize rapidly to give 2, 4-bis(phenylimino)-1,3-diphosphetanes 7 which in solution exist as mixtures of the E and Z isomers. Via a NaOH-catalyzed elimination of hexamethyldisiloxane these cyclic phosphines 7 can also be obtained from the adducts of phenyl isocyanate and bis(trimethylsilyl)phosphines 1. Taking the thermally sufficiently stable tert-butyl derivative 7 c as an example, the temperature dependence of n.m.r. spectra is discussed in detail.     

Umsetzungen des Tetrakis[bis(trimethylsilyl)methyl]dialans(4) mit Methylisothiocyanat und Phenylisocyanat – Insertion in die Al?Al-Bindung bzw. Fragmentierung

Reactions of Tetrakis[bis(trimethylsilyl)methyl]dialane(4) with Methylisothiocyanate and Phenylisocyanate – Insertion into the Al? Al Bond and Fragmentation Tetrakis[bis(trimethylsilyl)methyl]dialane(4) 1 reacts with methyl isothiocyanate under cleavage of the C?S double bond and insertion of the remaining isonitrile fragment into the Al? Al bond. As shown by crystal structure determination a three-membered AlCN heterocycle ( 4 ) is formed by the interaction of the nitrogen lone pair with one unsaturated Al atom leading to an acute angle at the aluminium center N? Al? C of 36.6°. In contrast the reaction with the hard base phenyl isocyanate yields a mixture of many unknown compounds, from which only one ( 5 ) could be isolated in a very poor yield. The crystal structure of 5 reveals only one dialkyl aluminium fragment and a chelating ligand formed by the trimerization of the isocyanate under loss of one CO group and addition of a hydrogen atom. 5 was also synthesized by the specific reaction of the chloro dialkyl aluminium compound (R = CH(SiMe₃)₂) with Li[H₅C₆? N?C(O)? N(C₆H₅)? C(O)? N(H)? C₆H₅].     

121Sb-Mößbauer-Spektren. IV. Benzamidinkomplexe des Antimon(V) Die Kristallstruktur von [Ph2Cl2Sb(N2Me2CPh)]

¹²¹Sb Mössbauer Spectra. IV. Benzamidine Complexes of Antimony(V). Crystal Structure of [Ph₂Cl₂Sb(N₂Me₂CPh)] The ¹²¹Sb Mössbauer spectra of the octahedral benzamidine complexes [Cl₄Sb[BAN)]] ( I ), [Ph₂Cl₃Sb(BAN)] ( II ), [Ph₂Cl₂Sb(BAN)] ( III ), and [Ph₃ClSb(BAN)] ( IV ) (BAN = N,N′-dimethyl-benzamidine) were measured at 4.2 K. The configuration of the complexes II–IV is derived from the values of the quadrupol split. In II the phenyl group is arranged in the axis, III contains both phenyl groups in equatorial position, located in trans-position to the N atoms of the chelate ligand, whereas in IV one phenyl group is placed axially, the other two are in equatorial position. The measurements are supplemented by the vibrational spectra below 600 cm^?1. Complex III crystallizes in the monoclinic space group P2₁/c with four formula units per unit cell. In addition, four molecules of CCl₄ per unit cell are placed in cavities of the lattice. The refinement has been carried on to an R-value of 6.5%, taking into account 1 729 unique, observed reflexions. The structure consists of discrete molecules of [Ph₂Cl₂Sb(N₂Me₂CPh)], in which the antimony atoms are surrounded by the N atoms of the chelate ligand, the phenyl groups and the two axial Cl atoms in distorted octahedral arrangement. The planes of the phenyl rings form dihedral angles with the equatorial plane of 129° and 143°.     

Quantum-Chemical Study of the Structure of Cyanophosphines and Their Oxides

The structure of cyanophosphines and their oxides was studied by ab initio (RHF/6-31G^**) and semiempirical (PM3) methods. Both methods predict that MeOP(CN)₂, (MeO)₂PCN, and (MeO)₂P(O)CN exist in noneclipsed antiperiplanar and synclinal conformations. The calculation results nicely agree with measured dipole moments and Kerr constants of these compounds. The phenyl and diphenyl derivatives PhP(CN)₂, Ph₂PCN, Ph(Et)PCN, and Ph₂P(O)CN prefer forms in which the phenyl ring plane is eclipsing the phosphorus lone electron pair or the phosphoryl bond. The interactions of the phosphorus lone electron pair with the phenyl ring and with the cyano group are lacking in the title compounds.     

Tris­[di­phenyl(2‐pyridyl)­phosphine]‐μ3‐iodo‐tri‐μ3‐sulfido‐sulfidotrisilvertungsten di­chloro­methane hemisolvate

The title compound, [Ag₃WIS₄(C₁₇H₁₄NP)₃]·0.5CH₂Cl₂, is a cubane‐type heterometallic cluster containing di­phenyl(2‐pyridyl)­phosphine (Ph₂PPy). The pyridyl group of Ph₂PPy remains uncoordinated, so the Ph₂PPy ligand is monodentate and coordinates to one Ag atom. The W atom and three Ag atoms form a distorted tetrahedral geometry, capped by one I atom and three S atoms.     

The catalytic carbonylation at atmospheric pressure of phenyl azide to PhNCO,PhNHCONHPh and PhNHCOOEt

The catalytic activities of rhodium(I) complexes in the carbonylation of phenyl azide at atmosphere pressure, leading to the corresponding isocyanate have been studied. [Rd(DPE)₂] Cl and RhCl(CO)(PPh₃)₂ are the most active catalysts, and maintain their high activity even in the presence of aniline (which gives diphenylurea) or ethanol (which gives carbamate).     

1,3,5‐Triphenyladamantane and 1,3,5,7‐tetraphenyladamantane

In 1,3,5‐triphenyladamantane, C₂₈H₂₈, (I), and 1,3,5,7‐tetraphenyladamantane, C₃₄H₃₂, (II), the molecules possess symmetries 3 and , and are situated across threefold and fourfold improper axes, respectively. The molecules aggregate by means of extensive C—H...π interactions. In (I), the pyramidal shape of the molecules dictates the formation of dimers through a `sixfold phenyl embrace' pattern. The dimers are linked to six close neighbors and constitute a primitive cubic net [H...π = 2.95 (2) and 3.02 (2) Å]. Compound (II) is isomorphous with tetraphenyl derivatives EPh₄ of group 14 (E = C–Pb) and ionic salts [EPh₄][BPh₄] (E = P, As and Sb). The multiple C—H...π interactions arrange the molecules into chains, with a concerted action of CH (phenyl) and CH₂ (adamantane) groups as donors [H...π = 3.15 (2) and 3.44 (2) Å, respectively]. The additional interactions with the methylene groups (four per molecule) are presumably important for explaining the high melting point and insolubility of (II) compared with the EPh₄ analogs.     

Sulphur substituted organometallic compounds III. Reactions of Ph3SnCH2CH2SC6H4Me-p with some electrophilic reagents

Two distinct types of reactions of electrophiles, EN, with Ph₃SnCH₂CH₂SC₆H₄Me-p (I) have been established. Thus I₂ and HgCl₂ cleave the phenyltin bond: I + EN → Ph₂(N)SnCH₂CH₂SC₆H₄Me-p + PhE (E  I, N  I; E  HgCl, N  Cl) while from the reactions of Br₂ and MeI, as well as of ArSCl, as previously reported, ethylene is evolved: I + EN → Ph₃SnN + CH₂CH₂ + ESC₆H₄Me-p (E  Br, N  Br; E  Me, N  I)     

Solution studies of triorganotelluronium salts

Evidence for telluronium ylid formation via the salt method is obtained for Ph₂Te(CH₂COPh)Br, but generally telluronium salts (aryl)₂Te(CH₂R)X rapidly dissociate in chloroform solution to (aryl)₂Te and RCH₂X. The relative rates of dissociation of Ph₂(CH₃)TeX in CHCl₃ are: X = I > Br ～ NCS > Cl > PhCOO. Conductivity and ¹H NMR data suggest the salts Ph₂(CH₃)TeX to be covalent and at least dimeric in CHCl₃, but more ionic in DMSO and, to a lesser extent, a DMF. IR data indicate association in solid Ph₂(CH₃)Tel. Kinetic data show that the reaction of CH₃I with excess Ph₂Te (solvent) affords an equilibrium mixture of ionic and covalent forms of Ph₂(CH₃)Tel, the ionic species being formed via the covalent one. Spin trapping experiments with phenyl(t-butyl)nitrone indicate that oxidative addition of alkyl halides to Ph₂Te and redcutive elimination of CH₃SCN from Ph₂ (CH₃)Te(NCS) proceed via radical pathways. A mechanism is proposed for oxidative addition which involves the preformation of a charge transfer complex of RX (alkyl halide) and diphenyltelluride.     

Über Polygermane. VI. 1,4-Diiodoctaphenyltetragerman l-(Ph2Ge-)4l,Kristallstruktur und Schwingungsspektren

On Polygermanes. VI. 1,4-Diiodooctaphenyltetragermane I-(Ph₂Ge-)₄I, Crystal Structure and Vibrational Spectra The crystal structure of the title compound has been determined and refined to a R of 0.060. The arrangement of the heavy atoms in the six membered chain I-Ge₄-I is all trans with a fully staggered conformation of the substituents. The torsion of the phenyl rings results in a molecular propeller with eight wings (symmetry C_i). Distances: Ge—Ge 245.1 (1) and 245.9 (2), Ge—I 255.9 (1) pm. The packing of the I-(Ph₂Ge-)₄I molecules resembles a tetragonal body centred sphere packing with coordination number (10+4). Domains for the 12 normal vibrations of the chain I-Ge₄-I are given.     

Zur Kenntnis des Bisphenyl-bis(dipyridyl)chrom(II) und des Lithium-tetraphenylochromat(II)

On bisphenyl-bis(dipyridyl) chromium(II) and lithium tetraphenylo chromate(II) By reaction of Ph₂CHCrCl₂ · 2 THF with two moles of phenyl lithium Ph₂CHCrPh₂ is obtained in solution. With this solution we prepared the new Cr(II) compounds CrPh₂ · 2 bipy and Li₂Ph₄ · 4 THF by addition of 2,2′-bipyridine and two moles of further phenyl lithium, respectively. During this reactions the diphenylmethyl group is cleaved under reduction of Cr(III) to Cr(II). Li₂CrPh₄ · 4 THF is an example of a new group of high spin organochromates(II).     

Chemie polyfunktioneller moleküle: LXXVI. Metallcarbonyl-, metallnitrosylcarbonyl-und metallnitrosyl-komplexe des bis(diphenylphosphino)amins

The compound Ph₂PN(H)PPh₂ (I) reacts under special conditions with M(CO)₆ (M  Cr, Mo), Fe(NO)₂(CO)₂ and Co(NO)(CO)₃ to give the new complexes cis-M(CO)₂[Ph₂PN(H)PPh₂]₂ (III, IV), [Fe(NO)₂(CO)Ph₂P]₂NH (V), [Fe(NO)₂Ph₂-PN(H)PPh₂]₂ (VI) and Co(NO)(CO)₂Ph₂PN(H)PPh₂ (VII). Compound VI can also be prepared reacting V with I. For III and IV proton NMR spectra indicate some interaction between o-protons of the phenyl rings and cis-M(CO)₂ groups. VI exists an eight-membered ring complex without a metal-metal bond. On the basis of spectroscopic data VII seems to exist in two conformers.     

Eine carben—metallbindung in [3.3.0]-nickelabicyclen

The complex (Ph₃P)Ni(PhNCNPh) (II) is formed from (Ph₃P)₂Ni(PhNCNPh) (I) in toluene at 60°C. II can also be prepared directly from (COD)₂Ni, Ph₃P and PhNCNPh (45% yield). (COD)₂Ni reacts with dairylcarbodiimides in THF to give (ArNCNAr)₃Ni(THF) (VIII). The structure of VIIIa (Ar  phenyl) has been determined by X-ray crystallography. The molecule is shown to contain a [3.3.0]nickela bicyclic group in which the carbodiimide molecules are linked to form a 2,5,8-h³-carbene ligand. Some properties and reactions of II and VIII are described.     

Phénylhalogénohydrodigermanes

The symmetric and unsymmetric phenylchlorohydrodigermanes can be isolated or characterized via partial halogenation of the Ge? H bonds of the symmetrical phenylhydrodigermanes Ph₂(H)GeGe(H)₂Ph, Ph(H)₂GeGe(H)₂Ph by chloromethyl methyl ether and carbontetrachloride. Some of these phenylchlorohydrodigermanes are formed by insertion of phenylchlorogermylene (PhGeCl) on the Ge? H or Ge? Cl bonds of the phenylchlorohydrogermanes. The hydrolysis of the monochloro phenylhydrodigermanes Ph₂(Cl)GeGe(H)₂ and Ph(Cl)(H)GeGe(H)₂Ph leads to the phenyl phenylhydrogermyl digermoxanes [Ph₂(H)GeGePh₂]₂O and [Ph(H)₂GeGe(H)Ph]₂O. Treatment of these oxides with the concentrated aqueous solutions of hydracides leads to the monofluorinated, brominated and iodinated phenylhydrodigermanes Ph₂(H)GeGe(X)Ph₂ and Ph(H)₂GeGe(H)(X)Ph (X) = F, Br, I). Phenylchlorohydrodigermanes decompose thermally by α-elimination on one germanium atom with formation of germylene and phenylchlorohydrogermane. The physico-chemical IR. and NMR. study of these phenylhalogenohydrodigermanes indicates that, if the vGe? H frequency variations are mostly linked to the inductive effects of the substituents on the same germanium, the variations of the chemical shifts of the Ge? H protons seem to be due to many factors and especially to the inductive effect of the substituents on the germanium and the magnetic anisotropy of the Ge? X bonds.     

Anionic copolymerization of isocyanates with ketenes

Diphenyl-, phenylethyl, and phenylmethylketene have been copolymerized with phenyl isocyanate by use of sodium naphthalene in dimethylformamide (DMF) at ?45°C. Reactivity ratios of phenyl isocyanate (r₂) with diphenylketene (r₁) were r₁ = 0.10, r₂ = 0.29; with phenylethylketene (r₁) were r₁ = 1.6, r₂ = 0.10; and with phenyl methyl ketene (r₁) were r₁ = 4.8, r₂ = 0.02. The same initiator and solvent system were used for homopolymerization of phenylethylketene and copolymerization with m-chloro-, p-chloro-, p-methoxy-, and m-methoxyphenyl isocyanate as well as with phenyl isocyanate. Molecular weights ranged from 1740 to 4000. The effect of substituents on the order of isocyanate incorporation into the copolymer was m-Cl = p-Cl > m-MeO > H > p-MeO. Phenylethylketene was also copolymerized with m-methoxyphenyl, p-methoxyphenyl, and p-tolyl isocyanate in tetrahydrofuran (THF) at ?78°C. Molecular weights ranged from 2800 to 10,500. The least reactive isocyanate was incorporated into the copolymer to a greater extent in this solvent than in the more polar DMF. DTA showed the presence of crystallinity only in polymers of high isocyanate content. The ketenes copolymerized less readily with alkyl isocyanates, such as ethyl, n-butyl, n-hexyl, and cyclohexyl isocyanate, than with the aromatic isocyanates when sodium naphthalene was used in either DMF or THF.     

Über Polygermane. VII [1]. Kristallstruktur von Dodecaphenylcyclohexagerman · Ditoluol

On Polygermanes. VII. Crystal Structure of Dodecaphenylcyclohexagermane Ditoluene The crystal structure of the title compound ( 1 d ) has been determined, refined to a R of 0.071, and compared with the structure of Ge₆Ph₁₂ · 7 benzene ( 1 c ). The molecular structure of Ge₆Ph₁₂ ( 1 ) is a Ge₆-chair with 6 axial and equatorial phenyl substituents respectively. The two toluene molecules in 1 d sandwich 1 above and below the plane of the six-membered ring resulting in steeper axial phenyl groups, stronger rippling of the Ge₆-chair and stretched Ge–Ge distances (246.3 pm) compared to 1 c . 1 has C_i-symmetry in both structures with nearly identical torsion of the phenyl groups. The Ge₆(Ph_eq)₆-part of the molecule approximates C_2h-symmetry. The arrangement of any two phenyl groups realizes largely either a parallel or a perpendicular setting of their respective planes. The joint conformation found is a normal conformation for molecules of the type X₆Ph₁₂.