Cyclooctadienes alkylation

Abbreviations Aik, alkyl AN, acetonitrile Ar, aryl Bu, butyl cod, 1,5-cyclooctadiene Cp, cy-clopentadienyl Cp , pentamethylcyclopentadienyl Cy, cyclohexyl dppm, diphenylphosphinome-thane dpme, Ph2PC2H4PMe2 Et, ethyl fod, 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octane-dionate HOMO, highest occupied molecular orbital LUMO, lowest unoccupied molecular orbital Me, methyl MO, molecular orbital nbd, norbornadiene Nuc, nucleophile OTf, triflate Ph, phenyl Pr, propyl py, pyridine THE, tetrahydrofuran TMEDA V,V,M,M-tetramethylethylenediamine. 

Abbreviations acac, acetylacetonate Aik, alkyl AN, acetonitrile bpy, 2,2 -bipyridine Bu, butyl cod, 1,5- or 1,4-cyclooctadiene coe, cyclooctene cot, cyclooctatetraene Cp, cyclopentadienyl Cp, pentamethylcyclopenladienyl Cy, cyclohexyl dme, 1,2-dimethoxyethane dpe, bis(diphenyl-phosphino)ethane dppen, cis-l,2-bis(di[Atenylphosphino)ethylene dppm, bis(diphenylphosphino) methane dppp, l,3-bis(diphenylphosphino)propane eda,ethylenediamine Et,ethyl Hal,halide Hpz, pyrazole HPz, variously substituted pyrazoles Hpz, 3,5-dimethylpyrazole Me, methyl Mes, mesityl nbd, notboma-2,5-diene OBor, (lS)-endo-(-)-bomoxy Ph, phenyl phen, LlO-phenanthroline Pr, f opyl py, pyridine pz, pyrazolate Pz, variously substituted pyrazolates pz, 3,5-dimethylpyrazolate solv, solvent tfb, tetrafluorobenzo(5,6]bicyclo(2.2.2]octa-2,5,7-triene (tetrafluorobenzobanelene) THE, tetrahydrofuran tht, tetrahydrothicphene Tol, tolyl. 

Abbreviations aapy, 2-acetamidopyridine Aik, alkyl AN, acetoniuile Ar, aryl Bu, butyl cod, 1,5-cyclooctadiene COE, cyclooctene COT, cyclooctatetraene Cp, cyclopentadienyl Cp , penta-methylcyclopentadienyl Cy, cyclohexyl DME, 1,2-dimethoxyethane DME, dimethylformamide DMSO, dimethyl sulfoxide dmpe, dimethylphosphinoethane dppe, diphenylphosphinoethane dppm, diphenylphosphinomethane dppp, diphenylphosphinopropane Et, ethyl Ec, feirocenyl ind, inda-zolyl Me, methyl Mes, mesitylene nb, norbomene orbicyclo[2.2.1]heptene nbd, 2,5-norbomadiene OTf, uiflate Ph, phenyl PPN, bis(triphenylphosphoranylidene)ammonium Pi , propyl py, pyridine pz, pyrazolate pz, substituted pyi azolate pz , 3,5-dimethylpyrazolate quin, quinolin-8-olate solv, solvent tfb, teti afluorobenzobaiTelene THE, tetrahydrofuran THT, tetrahydrothiophene tmeda, teti amethylethylenediamine Tol, tolyl Tp, HB(C3H3N2)3 Tp , HB(3,5-Me2C3HN2)3 Tp, substituted hydrotiis(pyrazol-l-yl)borate Ts, tosyl tz, 1,2,4-triazolate Vin, vinyl. 

In 2004, Dieguez et al. reported the development of novel C2-symmetric dithioether ligands derived from the corresponding binaphthyl or biphenanthryl diols. Thus, various (i )-binaphthyl dithiols substituted by alkyl groups on the sulfur atom in order to increase the steric bulk were synthesised, and the corresponding mononuclear cationic Ir(I) -cyclooctadiene complexes were prepared and characterised (Scheme 8.20). NMR studies demonstrated that, in all cases, the coordination of the ligands proceeded with complete stereoselectivity at the... 

In contrast to Ni, alkylpalladium precursors can be easily prepared and isolated owing to their greater stability (Scheme 2). The monomethyl chloride adducts of formula (diimine)PdMeCl can be conveniently synthesized via diimine displacement of other weakly coordinating ligands, such as COD from Pd(COD)MeCl (COD = 1,5-cyclooctadiene) [44], or by in situ alkylation-complexation with tetramethyltin [52], The chloride ligand can then be cleanly abstracted by metathesis with NaBAF... 

Towards the end of this section it may be worthwhile to point out some new reactions with high-valent metals and TBHP. The first is a pyridinium dichromate PDC-TBHP system134. Nonsubstituted or alkyl-substituted conjugated dienes, such as 1,3-cyclooctadiene (87) and others (also linear dienes), yield keto allyl peroxides 88 (equation 18), whereas phenyl-substituted dienes such as 1,4-diphenylbutadiene (89) gave diketo compounds, 90 (equation 19). In further research into a GIF-type system135 with iron and TBHP, limonene gave a mixture of products with carvone as the major product. The mechanism is thought to proceed initially by formation of a Fe(V)-carbon... 

Ketone rac-13 was transformed into the corresponding silylenolether and by Pd(II)-mediated Saegusa oxidation [14] into a, -unsaturated ketone rac-14. By alkylative enone transposition comprising methyl lithium addition and pyridinium chlorochromate (PCC) oxidation [15], rac-14 was finally converted into the racemic photo cycloaddition precursor rac-6. In conclusion, the bicyclic irradiation precursor rac-6 was synthesized in a straightforward manner from simple 1,5-cyclooctadiene (11) in nine steps and with an overall yield of 21%. 

Addition of alane and borane to alkenes affords a host of alkylated alanes and boranes with various reducing properties (and sometimes bizarre names) diisobutylalane (Dibal-H ) [104], 9-borabicyclo[3.3.1]nonane (9-BBN) (prepared from borane and 1,5-cyclooctadiene) [705], mono- [106,107] and diiso-pinocampheylborane (B-di-3-pinanylborane) (both prepared from borane and optically active a-pinene) [108], isopinocampheyl-9-borabicyclo[3.3.1 Jnonane alias B-3-pinanyl-9-borabicyclo[3.3.1]nonane (3-pinanyl-9-BBN) (prepared from 9-borabicyclo [3.3.1]nonane and a-pinene) [709], NB-Enanthrane prepared from 9-borabicyclo[3.3.1]nonane and nopol benzyl ether) [770] and others. ... 

Kuwano and his co-workers also found a more effective reaction system by using [Cp( -C3H5)Pd] 123 in place of [Pd( 7 -C3H5)(cod)]BF4 117 as a palladium catalyst precursor. In this reaction system, benzylic alkylation of benzyl carbonates with a variety of active methine compounds gives alkylated products in excellent yields even in the absence of a base (Equation (47)). Addition of a catalytic amount of 1,5-cyclooctadiene (cod) to this reaction system promotes benzylic alkylation of benzylic carbonates with a variety of active methine compounds to give the... 

Since the reactivity of double bonds in electrophilic bromination increases drastically with increasing alkyl substitution, selective monoaddition to the more substituted double bond in nonconjugated dienes can be accomplished with pyridin hydrobromide perbromide.264 Chlorination265 and bromination266 of c/s,cis-1,5-cyclooctadiene lead to the expected dihalogen and tetrahalogen derivatives. 

Coordination catalysts of formula (I), where M is Pd, Q is an alkyl, S is a halogen, R1 is H or an alkyl (1-4 carbon atoms), preferably a methyl group, and R2 is a hydrocarbyl (1-4 carbon atoms), preferably a methyl group, may be made by the reaction of the corresponding 1,5-cyclooctadiene (COD) Pd complex with the appropriate diimine. When M is Ni, (I) can be made by the displacement of another ligand, such as a dialkylether or a polyether such as 1,2-dimethoxyethane, by an appropriate diimine ... 

As discussed in Sects. 2.1 and 2.2.8 control of molar mass is an important aspect in the large-scale polymerization of dienes. In Nd-catalyzed polymerizations the control of molar mass is unique amongst Ziegler/Natta catalyst systems as standard molar mass control agents such as hydrogen, 1,2-butadiene and cyclooctadiene which are well established for Ni- and Co-systems do not work with Nd catalysts [82,206,207]. The only known additives which allow for the regulation of molar mass without catalyst deactivation are aluminum alkyls, magnesium alkyls, and dialkyl zinc. 

Ishii and coworkers developed a Mn(OAc)2-catalyzed hydrophosphonation of alkenes 40 (Fig. 47) [271]. The active Mn(III) catalyst is generated by reaction of Mn(OAc)2 with oxygen. Hydrogen abstraction from diethyl phosphite 169 forms a phosphonyl radical, which adds to 40. The resulting alkyl radical is reduced by 169 to continue the chain reaction. Alkylphosphonates 170 were isolated in 51-84% yield. With (3-pinene a cyclobutylcarbinyl radical ring opening was observed in 32% yield, while 1,5-cyclooctadiene underwent a tandem radical addition/ transannular 5-exo cyclization (cf. Fig. 38). 

The final series of five procedures presents optimized preparations of a variety of useful organic compounds. The first procedure in this group describes the preparation of 3-BROMO-2(H)-PYRAN-2-ONE, a heterodiene useful for (4+2] cycloaddition reactions. An optimized large scale preparation of 1,3,5-CYCLOOCTATRIENE, another diene useful for [4+2] cycloaddition, is detailed from the readily available 1,5-cyclooctadiene. Previously, the availability of this material has depended on the commercial availability of cyclooctatetraene at reasonable cost. A simple large scale procedure for the preparation of 3-PYRROLINE is then presented via initial alkylation of hexamethylenetetramine with (Z)-1,4-dichloro-2-butene. This material serves as an intermediate for the preparation of 2,5-disubstituted pyrroles and pyrrolidines via heteroatom-directed metalation and alkylation of suitable derivatives. The preparation of extremely acid- and base-sensitive materials by use of the retro Diels-Alder reaction is illustrated in the preparation of 2-CYCLOHEXENE-1.4-DIONE, a useful reactive dienophile and substrate for photochemical [2+2] cycloadditions. Functionalized ferrocene derivatives... 

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