Olefins cyclooctadiene

Catalytic Asymmetric Hydroboration. The hydroboration of olefins with catecholborane (an achiral hydroborating agent) is cataly2ed by cationic rhodium complexes with enantiomericaHy pure phosphines, eg, [Rh(cod)2]BE4BINAP, where cod is 1,5-cyclooctadiene and BINAP is... 

A particularly useful phosphine ligand for the cobalt carbonyl catalyst is a bicyclic tertiary phosphine available from 1,5-cyclooctadiene, phosphine, and an a-olefin ... 

A family of cyclopentadiene(Cp)-containing iron-olefin complexes has been pioneered by Jonas [13-15]. The complexes 38-40 (Scheme 7) can be obtained in a large scale from ferrocene 37 under reducing conditions in the presence of suitable coordinating olefins. Complex 38 is a highly air-sensitive, crystalline material, whereas complexes 39 and 40 are more robust due to their cyclooctadiene (cod)... 

Section B of the Scheme 9.1 shows several procedures for the synthesis of ketones. Entry 6 is the synthesis of a symmetrical ketone by carbonylation. Entry 7 illustrates the synthesis of an unsymmetrical ketone by the thexylborane method and also demonstrates the use of a functionalized olefin. Entries 8 to 10 illustrate synthesis of ketones by the cyanide-TFAA method. Entry 11 shows the synthesis of a bicyclic ketone involving intramolecular hydroboration of 1,5-cyclooctadiene. Entry 12 is another ring closure, generating a potential steroid precursor. 

The Diels-Alder adduct of 1,5-cyclooctadiene with hexachlorocyclo-pentadiene was homopolymerized or copolymerized (113) with cyclic olefins using tungsten halide salts with either organoaluminum or organo-tin cocatalyst to give thermally stable flame- and oil-resistant polymers. 

With electron-rich olefins, the rate of addition to a second thione is faster than that of the combination of the intermediate diradical to thietane. By substituting these olefins, however, with groups that provide steric hindrance, the reaction of the diradical with another thione molecule can be inhibited. Irradiation of thiobenzophenone and 1,3-cyclooctadiene, propenylbenzene. 

Significant advances in organonickel chemistry followed the discovery of frtzws,fraws,fraws-(l,5,9-cyclododecatriene)nickel, Ni(cdt), and bis(l,5-cycloocta-diene)nickel Ni(cod)2 by Wilke et. al.1 In these and related compounds, in which only olefinic ligands are bonded to the nickel, the metal is especially reactive both in the synthesis of other compounds and in catalytic behavior. Extension of this chemistry to palladium and to platinum has hitherto been inhibited by the lack of convenient synthetic routes to zero-valent complexes of these metals in which mono- or diolefins are the only ligands. Here we described the synthesis of bis(l,5-cyclooctadiene)platinum, tris(ethylene)-platinum, and bis(ethylene)(tricyclohexylphosphine)platinum. The compound Pt(cod)2 (cod = 1,5-cyclooctadiene) was first reported by Muller and Goser,2 who prepared it by the following reaction sequence ... 

Other tris(olefin)platinum(0) complexes (where olefin represents a strained olefin such as bicyclo[2.2.1]heptene, dicyclopentadiene, or trans-cyclooctene) may be similarly obtained by direct displacement of 1,5-cyclooctadiene, often in quantitative yield.6... 

Di-/i-chloro-bis(7)4-1,5-cyclooctadiene)dirhodium(l), [RhCl(l,5-C8Hi2)]2, has been prepared in 60% yield by reducing rhodium trichloride hydrate in the presence of excess olefin in aqueous ethanol.1 In the present preparation the yield has been greatly increased (to 94%). Two related complexes, [RhCl(l,5-C6Hio)]22 and [RhCl(C6H12)2]2, are similarly prepared in high yield from 1,5-hexadiene and 2,3-dimethyl-2-butene, respectively. 

When the ruthenium Schiff base olefin metathesis catalyst was used to polymerize cyclooctadiene Mw s > 100,000 Da were obtained. Although only 12 Schiff bases were identified as effective in these polymerizations, additional analogs are anticipated to be reported from the University of Ghent group. 

Norbornadiene- and cyclooctadiene-containing bridged olefin metathesis catalyst were also prepared by the author in the current application and are illustrated below. 

These compounds have been obtained indirectly by reactions of silylated acetylenes with metal carbonyls or olefin complexes. Thus, trimethylsilylphenylacetylene reacts with rj5-cyclopentadienylcobalt dicarbonyl, cobaltocene, or rjs-cyclopentadienyl-(l,3-cyclooctadiene) cobalt, in refluxing xylene, to give a mixture of cis- and trans-bis-(trimethylsilyl)cyclobutadiene complexes (R = Me, R = Ph) 68, 127, 137) ... 

Conjugated dienes can be dimerized or trimerized at their 1,4 positions (formally, 4 + 4 and 4 + 4 + 4 cycloadditions) by treatment with certain complexes or other transition-metal compounds.1088 Thus butadiene gives 1,5-cyclooctadiene and 1,5,9-cyclodo-decatriene.1089 The relative amount of each product can be controlled by use of the proper catalyst. For example, Ni P(OC6H4-o-Ph)3 gives predominant dimerization, while Ni(cyclooctadiene)2 gives mostly trimerization. The products arise, not by direct 1,4 to 1,4 attack, but by stepwise mechanisms involving metal-olefin complexes.1090... 

Cyclic thionocarbonates (41) can be cleaved to olefins (the Corey-Winter reaction)274 by heating with trimethyl phosphite275 or other trivalent phosphorus compounds276 or by treatment with bis(l,5-cyclooctadiene)nickeI.277 The thionocarbonates can be prepared by treatment of 1,2-diols with thiophosgene and 4-dimethyIaminopyridine (DMAP) 278... 

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