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Nonane complexes

Prior to this work, Mosner and Yamaguchi" reported similar reduction with an LAH-quinine combination however, no example of acetylenic ketone was attempted. In a later study, Midland et al. developed a-pinene-9-Borabicyclo [3.3.1] nonane complex as an excellent reagent for the reduction of a,P-acetylenic ketones and observed high asymmetric induction in aliphatic systems (Table 21.1). [Pg.144]

Facile reaction of a carbon nucleophile with an olefinic bond of COD is the first example of carbon-carbon bond formation by means of Pd. COD forms a stable complex with PdCl2. When this complex 192 is treated with malonate or acetoacetate in ether under heterogeneous conditions at room temperature in the presence of Na2C03, a facile carbopalladation takes place to give the new complex 193, formed by the introduction of malonate to COD. The complex has TT-olefin and cr-Pd bonds. By the treatment of the new complex 193 with a base, the malonate carbanion attacks the cr-Pd—C bond, affording the bicy-clo[6.1,0]-nonane 194. The complex also reacts with another molecule of malonate which attacks the rr-olefin bond to give the bicyclo[3.3.0]octane 195 by a transannulation reaction[l2.191]. The formation of 194 involves the novel cyclopropanation reaction of alkenes by nucleophilic attack of two carbanions. [Pg.47]

The alkynyl reagent 9 was recently introduced for the dia stereoselective synthesis of tertiary propargylic alcohols144. 9 can be prepared as a solid 1 1 complex with tetrahydrofuran by treatment of 9-methoxy-9-borabicyclo[3.3.1]nonane with (trimethylsilylethynyl)lithium, followed by addition of boron trifluoride-diethyl ether complex. The nucleophilic addition of reagent 9 to (R)-2-methoxy-2-methylhexanal (10) afforded a mixture of the diastereomers 11 with a considerable preference to the nonchelation-controlled (3S,4R)-isomer144. [Pg.62]

In a second set of examples, it was shown that the stereoselectivity of the aldehyde allylborations of 9-[( T)-l-trimethylsilyl- or l-trimethylstannyl-2-butenyl]-9-borabicyclo[3.3.1]nonane is controlled to a significant extent by conversion to an ate complex by treatment with butyllithium, MT-butyllithium or pyridine19. [Pg.324]

The potential of Fischer carbene complexes in the construction of complex structures from simple starting materials is nicely reflected in the next example. Thus, the reaction of alkenylcarbene complexes of chromium and tungsten with cyclopentanone and cyclohexanone enamines allows the di-astereo- and enantioselective synthesis of functionalised bicyclo[3.2.1]octane and bicyclo[3.3.1]nonane derivatives [12] (Scheme 44). The mechanism of this transformation is initiated by a 1,4-addition of the C -enamine to the alkenylcarbene complex. Further 1,2-addition of the of the newly formed enamine to the carbene carbon leads to a metalate intermediate which can... [Pg.90]

Template condensation reactions of the nickel(II) complex of 3,7-bis(2-aminoethyl)-l,3,5,7-tetraazabicyclo[3.3.1]nonane with formaldehyde and the appropriate primary diamines such as ethylenediamine, 1,4-butanediamine, and p-xylenediamine yield dinickel(II) complexes of bis-heptaazamacrocyclic ligands (716)-(718). Similarly, the dinuclear Ni11 complexes (719) and (720) were prepared by using [Ni(2,3,2-tet)](C104)2, formaldehyde, and NH2—(CH2)ra—NH2 ( = 2, 3, 4, 5, 6, 10) or melamine, respectively. [Pg.426]

Aliphatic amines, which are hard bases, are unfavorable for coordination to soft Ni°. If the principles of ligand preorganization and donor prepositioning are applied, however, (diamine)Ni° complexes are accessible, which has been demonstrated for complex (1020) with a rigid N,N -dimethyl-3,7-diazabicyclo[3.3.1 ]nonane ligand.2468... [Pg.501]

An enormous variety of solvates associated with many different kinds of compounds is reported in the literature. In most cases this aspect of the structure deserved little attention as it had no effect on other properties of the compound under investigation. Suitable examples include a dihydrate of a diphosphabieyclo[3.3.1]nonane derivative 29), benzene and chloroform solvates of crown ether complexes with alkyl-ammonium ions 30 54>, and acetonitrile (Fig. 4) and toluene (Fig. 5) solvates of organo-metallic derivatives of cyclotetraphosphazene 31. In most of these structures the solvent entities are rather loosely held in the lattice (as is reflected in relatively high thermal parameters of the corresponding atoms), and are classified as solvent of crystallization or a space filler 31a). However, if the geometric definition set at the outset is used to describe clathrates as crystalline solids in which guest molecules... [Pg.14]

The complexity of skeletal isomerization of decalin is depicted in Figures 8A and 8B. It shows that methylbicyclo[4.3.0]nonanes (MBCN1) are the... [Pg.287]

Water (alkyl lead) Complexation of sample with diethyldithiocarbamate extraction with pentane removal of water butylation extraction with nonane GC/AAS 1.25 ng/L 90-108 Chakra borti et al. 1984... [Pg.453]

Phosphacyclic diphosphines (73a) and (73b) with wide natural bite angles were synthesized and the effect of the phosphacyclic moieties on the coordination chemistry in the [(diphosphine) Rh(CO)2H] complexes was studied. Both NMR and IR spectroscopy showed that the phosphacyclic xantphos ligands exhibit an enhanced preference for diequatorial chelation compared to the diphenylphosphino-substituted parent compound. In the hydroformylation of 1-octene the introduction of the phosphacyclic moieties leads to higher reaction rates. The dibenzophospholyl- and phenoxaphosphino-substituted xantphos ligands exhibit a high activity and selectivity in the hydroformylation of trans-2- and 4-octene to linear nonanal. CO dissociation rates from the... [Pg.160]

Three generations of dendritic phosphines have been prepared from 3,5-diaminobenzoylglycine and 9-fluorenylmethoxycarbonyl-L-phenylalanine. The dendrimers were then attached to MBHA resin, treated with CH20 and Ph2PH, and converted to their Rh complexes. The polymer-supported complexes are excellent catalysts for the hydroformylation of alkenes, which could be recycled.283 The bidentate diphosphine A,A-bis-(P-(phosphabicyclo[3.3.1] nonan) methyl)aniline was prepared by phosphanomethylation of aniline. It forms a Rh-complex which is a highly regioselective catalyst in the hydroformylation of citronellene.284... [Pg.163]

The results of unsymmetrical 7r-acid bidentate ligands, e.g., (81), have in the hydroformylation of ra-octenes was described. The preparation of seven such ligands was described. Thus, [Rh-(acac)(cod)]-catalyzed hydroformylation of ra-octene in the presence of a phosphinite ligand gave 94% ra-nonanal.295 A new upper-rim phosphacalix[4]arene 5,17-bis(diphenylphosphinomethyl)-25,26,27,28-tetrapropoxycalix[4]arene has been prepared. It reacted with [(cod)RhCl]2 to give a dirhodium complex that is an active catalyst for the hydroformylation of 1-octene and styrene.296 Rhodium complexes of [l-propyl-3-methylimidazolium+]2 [PhP(C6H4SO%)2] dissolved in the... [Pg.164]

The 10-57-5-hydridosiliconate ion 62 is known in association with lithium,323 tetrabutylammonium,101 and bis(phosphoranyl)iminium93 cations. It is synthesized by hydride addition to the 8-.S7-4-silane 63, which is derived from hexafluoroacetone.101 Benzaldehyde and related aryl aldehydes are reduced by solutions of 62 in dichloromethane at room temperature101 or in tetrahydrofuran at 0°96 within two hours. The alkyl aldehyde, 1-nonanal, is also reduced by 62 in tetrahydrofuran at O0.96 Good to excellent yields of the respective alcohols are obtained following hydrolytic workup. The reactions are not accelerated by addition of excess lithium chloride,96 but neutral 63 catalyzes the reaction, apparently through complexation of its silicon center with the carbonyl oxygen prior to delivery of hydride from 62.101... [Pg.62]

A process for the hydroformylation of 1-octene to nonanal was designed for an immobilised homogeneous catalyst. The production capacity was fixed at 100 kton of nonanal. Kinetic data reported for the rhodium catalyst complex of N-(3-trimethoxysilane-n-propyl)-4,5-bis(diphenylphosphino)-phenoxazine immobilised on silica, (2) was used as a starting point. Other process specifications are given in Table 3.8. [Pg.65]

These ate complexes are prepared by reaction of potassium hydride with a 9-alkyl-9-borabicyclo[3.3. l]nonane (9-R-9-BBN). [Pg.264]

Fig. 11.4. Electron ionization mass spectrum of nonanal. Unlike the previous example (toluene, Fig. 11.3), this 9-carbon alkyl aldehyde displays extensive fragmentation and a very low abundance molecular ion at mlz 142. The extensive degree of fragmentation exhibited by many compounds under El conditions makes manual interpretation complex and tedious. Consequently, computerized searches of spectral libraries find extensive use in compound identification. Fig. 11.4. Electron ionization mass spectrum of nonanal. Unlike the previous example (toluene, Fig. 11.3), this 9-carbon alkyl aldehyde displays extensive fragmentation and a very low abundance molecular ion at mlz 142. The extensive degree of fragmentation exhibited by many compounds under El conditions makes manual interpretation complex and tedious. Consequently, computerized searches of spectral libraries find extensive use in compound identification.
In comparison with the hydroboration and diborafion reactions, thioboration reactions are relatively limited. In 1993, Suzuki and co-workers reported the Pd(0)-catalyzed addition of 9-(alkylthio)-9-BBN (BBN = borabicyclo [3.3.1] nonane) derivatives to terminal alkynes to produce (alkylthio)boranes, which are known as versatile reagents to introduce alkylthio groups into organic molecules [21], Experimental results indicate that the thioboration reactions, specific to terminal alkynes, are preferentially catalyzed by Pd(0) complexes, e.g. Pd(PPh3)4, producing (thioboryl)alkene products, in which the Z-isomers are dominant. A mechanism proposed by Suzuki and co-workers for the reactions involves an oxidative addition of the B-S bond to the Pd(0) complex, the insertion of an alkyne into the Pd-B or Pd-S bond, and the reductive elimination of the (thioboryl)alkene product. [Pg.208]

Experimental Procedure 3.2.3. Intramolecular C-H Insertion of an Iron Carbene Complex 8-Phenylbicyclo[4.3.0]nonan-2-one... [Pg.306]

The additional presence of 1-nonanal serves as model for the formation of the linear hydroformylation product of 1-octene and its influence on catalyst solubility. The aldehyde lowers the complex solubility further (Fig. 19) as compared to the mixture with olefln only. [Pg.126]

The rhodium complex with bis(diphenylphosphino)phenoxazine was immobilized on silica using the sol-gel technique or by a direct grafting to commercially available silica [127]. Under standard hydroformylation conditions (CO/H2 atmosphere), a neutral hydridic complex (57) and cationic species (58) (Scheme 4.35) coexist on the support and act as a hydroformylation/hydrogenation sequence catalyst, giving selectively 1-nonanol from 1-octene 98% of 1-octene were converted to mainly linear nonanal which was subsequently hydrogenated to 1-nonanol. The... [Pg.231]

It is no coincidence that the first X-ray structure analysis of a transition metal-boryl complex [8] was made on the iridium complex jac-[IrH2(BC8Hi4)(PMe3)3] (2) [9] derived from the B—H activation of the 9-borabicyclo[3.3.1]-nonane (9-BBN)... [Pg.173]


See other pages where Nonane complexes is mentioned: [Pg.21]    [Pg.238]    [Pg.21]    [Pg.238]    [Pg.1031]    [Pg.78]    [Pg.455]    [Pg.266]    [Pg.325]    [Pg.21]    [Pg.374]    [Pg.464]    [Pg.156]    [Pg.154]    [Pg.161]    [Pg.101]    [Pg.616]    [Pg.255]    [Pg.278]    [Pg.143]    [Pg.389]    [Pg.597]    [Pg.860]    [Pg.172]    [Pg.263]   
See also in sourсe #XX -- [ Pg.303 , Pg.304 , Pg.305 , Pg.306 , Pg.307 , Pg.308 , Pg.309 , Pg.310 , Pg.311 , Pg.312 ]




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