Cycloocta-l,5-diene

P/A/)-5,6,7,8-Tetrahydrodibenzo ,c)cycloocta-l,3-dienes Oxidative Aryl Coupling with Thallium(lll) Oxidants General Procedures13 ... 

Methyl-2-nitrosopyridine reacted with (lZ,3Z)-cycloocta-l,3-diene to give the iV-pyridyl-l,2-oxazocine 132. Such a Diels-Alder reaction was conducted in the presence of a catalytic amount of an asymmetric bidentate ligand and a metal to provide an enantiomerically enriched cycloadduct however, the ee observed was only 4% (Equation 11) <2005WO068457>. 

The TT-allylpalladium intermediate 130, formed by the intramolecular carbopalladation of 129, could be trapped with the enolate of diethyl malonate, with BusSnPh, with piperidine, or with phenol to afford a variety of cycloocta-l,3-diene derivatives 131-134 (Scheme 43). "... 

Inoue, Y, Daino, Y, Hagiwara, S., Nakamura, H., and Hakushi, X, Direct photolysis at 185-254 nm of cycloocta-l,3-diene and cyclohepta-l,3-diene. Wavelength-independent photobehavior,/. 

With dienes and acetylenes, only M = Fe, Co or Ni showed activity. The Fe and Co systems gave many side products. Therefore, the Ni catalyst was studied in greater detail. Bis-(7r-cycloocta-l,5-diene)nickel(0) was equivalent to the Ziegler catalyst in hydrosilation of penta-1,3-diene. 

Since borane BH3 reacts with only one or two equivalents of a sterically hindered alkene, it is possible to prepare less reactive and more selective borane reagents R2BH and RBH2 respectively. In addition to disiamylborane 8 and thexylbo-rane 10, the 9-borabicyclo[3.3.1]nonane (9-BBN) 14 is an important reagent for hydroboration, since it is stable to air it is prepared by addition of borane 2 to cycloocta-l,5-diene 13 ... 

Thermal cyclodimcrization of methylenecyclopropane results in head-to-head cycloaddition (see Section 1.3.1.1.). By contrast the bis(cycloocta-l,5-diene)nickel(0) catalyzed reaction of methylenecyclopropane gives the head-to-tail dimerization product 6 in 9% yield in addition to a [3 + 2] dimer 7.20... 

Ring closure to cyclobutanes via valence isomerization of cycloocta-l,3,5-trienes is also possible when carbonyl functions are present in the ethane fragment. Thus, reaction of cyclohepta-2,4,6-trienone (tropone) with diazopropane gives 8,8-dimethylcycloocta-2,4,6-trienone (16, R = H), which rearranges quantitatively to 8,8-dimethylbicyclo[4.2.0]octa-2,4-dien-7-one (17, R = H).67... 

The ( /4-bicyclo[2.2.1]hepta-2,5-diene)bis( /3-2-propenyl)ruthenium(II) and (>/4-cycloocta-l,5-diene)bis(>/3-2-propenyl)ruthenium(II) complexes have previously been reported,5,6 but we present here scaled-up procedures that produce synthetically useful quantities of these compounds. The preparation of Grignard reagents is based upon the methods described by Eisch.7... 

The complexes ( /4-cycloocta-l, 5-diene)bis(>/3-2-methyl-l-propenyl)-ruthenium(II), [ Ru(i/4-C8H12)(02CCCl3) 2(p-02CCCl3)2(/i-0H2)], and [ Ru( 4-C7H8)(02CCF3) 2(p-02CCCl3)2(p-0H2)] may be prepared by procedures similar to those described for the related complexes in Sections D, E, and G. 

Similarly, (r/3-crotyl)(cycloocta-l,5-diene)palladium hexafluoro-phosphate can be activated with a with a co-catalyst such as AgBF4 or AgSbF6 (40). 

Amino-3-cyanofurans (307) are obtained by base catalyzed condensation of the acyloins (306) with malonodinitrile, and on acid hydrolysis yield the butenolides (308) (Scheme 80) (66CB1002). Diketene and an isocyanide react to give the lactone (309) in the presence of a tertiary base (73GEP2222405). When diphenylketene is treated with bis(cycloocta-l,5-diene)nickel and pyridine, the complex Ni(py)2(Ph2C=CO)2 is formed which is converted into compound (310) by carbon monoxide (78JOM(l52)C29). 

The formation of polymers containing [=CH(CH2)4CH=], units is possible through the ROMP of an appropriate cyclic diene, such as cycloocta-1,3-diene, or by a double-bond shift reaction of a polymer such as poly(l-pentenylene). Such units can be eliminated as cyclohexene so long as metathesis activity is present in the system360. The ROMP of 2,3-dihydropyran, initiated by Mo(CO)6/CBr4// v, has been reported361. 

The formation of the cyclooctatrienes was quenched in the presence of low concentrations of 2,5-dimethylhexa-2,4-diene or 2,3-dimethylbuta-l,3-diene. The photocyclization of the trienes was, however, unaffected by the presence of the dienes. The authors conclude that the primary photoreaction of intramolecular ortho cycloaddition involves the 3 tt, tt state of the arene and the subsequent cyclization of the cycloocta-l,3,5-triene arises from the singlet state. 

NCD = A derivative of bicyclo[4.2.0]octa-2,7-diene, a non-conjugated diene. COT = A derivative of cycloocta-l,3,5-triene. 

Using a relative rate method, rate constants for the gas-phase reactions of O3 with 1- and 3-methylcyclopentene, 1-, 3- and 4-methylcyclohexene, 1-methylcycloheptene, cw-cyclooctene, 1- and 3-methylcyclooctene, cycloocta-1,3- and 1,5-diene, and cyclo-octa-l,3,5,7-tetraene have been measured at 296 2 K and atmospheric pressure. The rate constants obtained (in units of 10-18 cm3 molecule-1 s-1) are as follows 1-methylcyclopentene, 832 24 3-methylcyclopentene, 334 12 1-methylcyclohex-ene, 146 10 3-methylcyclohexene, 55.3 2.6 4-methylcyclohexene, 73.1 3.6 1-methylcycloheptene, 930 24 d.s-cyclooclcnc, 386 23 1-methylcyclooctene, 1420 100 3-methylcyclooctene, 139 9 d.v.d.v-cycloocta-1,3-diene, 20.0 1.4 cycloocta- 1,5-diene, 152 10 and cycloocta-l,3,5,7-tetraene, 2.60 0.19 the indicated errors are two least-squares standard deviations and do not include the uncertainties in the rate constants for the reference alkenes (propene, but-l-ene, d.s-but-2-ene, trans-but-2-ene, 2-methylbut-2-ene, and terpinolene). These rate data were compared with the few available literature data, and the effects of methyl substitution have been discussed.50... 

Cycloocta-l,5-diens (Formel 41) in der Gasphase. Neben polymerem Material entstehen zu 2—3 % zwei isomere Substanzen, die als Bicyclo-[5,l,0]octen-(3) (Formel 42) und Tricyclo[3,3,0,02< ]octan (Formel 43) identifiziert werden konnten (280, 283). 

Direkte UV-Bestrahlung wandelt Cycloocta-l,3,5-trien (Formel 121) hauptsachlich in Bicyclo[4,2,0]octa-2,7-dien (Formel 122) und Tricyclo-[3,2,l,0a-8]oct-3-en (Formel 123) (58,222,340) um. Daneben werden noch all-trans-Octatetra-l,3,5,7-en (222) und Cyclo-octa-l,5-dien (58) nach-gewiesen. 

Styrene undergoes polymerisation with the cationic organonickel(II) complex / 3-methallyl ( /4-cycloocta-l,5-diene)nickel hexafluorophosphate [(MeAll) (Co<7)/W]+[PF]6 combined in situ with tricyclohexylphosphine. The product of such polymerisation is a styrene oligomer with Mn = 1900, characterised by a... 

Ir(H)2(PPh3)2 (solvent ] Cycloocta-l,S-diene, hexa-1,3-diene, 529,530 norbornadiene, butyraldehyde, alkynes ... 

Reaction of chromium atoms, l,5-cyclooctadiene(l,5-cod), and PF3 on the other hand yielded a separable mixture of [Cr(C8Hu)(PF3)3H] and (j74-cycloocta-l,5-diene)tetrakis(trifluorophosphine)chromium. The latter is readily converted to the former by warming a solution of it to 90°C (Scheme 3). This rearrangement is impaired under an atmosphere of PF3 and the 1,5-cod is preferentially displaced to give [Cr(PF3)6]. 

Olefinic complexes of copper have been reviewed in Volume 12 of this series (289). Since the appearance of this review, [Cu(cycloocta-l,6-diene)2]BF4 has been prepared by electrolysis of Cu(BP4)2 in methanolic diolefin at copper electrodes (231). Complexes (cycloocta-l,5-diene)Cu02C-CPg, (cyclooctatetrene)(Cu02C CPa)2, and (cyclo-octa-l,5-diene)(Cu02C CF3)a have been obtained as white or pale yellow solids by reacting CuOaC -CFg with the olefins in pentane or benzene, respectively (107). The structure of Cu2Gl2(trans-cyclooctene)3 (Fig. 10) has been determined (124) and is reminiscent of the structure of Cu2Cl2(PPh3)3 (Fig. 5). 

This reacts with cycloocta-1,5-diene or ewdo-dicyclopentadiene to give [Cu(diolefin)2]03S-CF3 complexes, and with cyclooctatetrene, cyclo-dodeca-l,5,9-triene, cycloocta-1,3-diene, or norbomylene to give Cu(olefin)03S-CF3 complexes cyclohepta-l,3,5-triene can replace benzene in the parent complex yielding Cu(CFgS03) J(triolefin). 

The systematic nomenclature of fused-ring thiiranes and thiirenes is based on their parent hydrocarbons, for example, 6-thiabicyclo[3.1.0]hexane 1, 9-thiabicyclo[6.1.0]non-4-ene 2, 3-oxa-6-thiabicyclo[3.1.0]hexane 3, and 9-thiabicy-clo[6.1.0]non-l(8)-ene 6. A different nomenclature, which is frequently used, especially for more complex structures, is based on the name of the parent cyclic olefins and the addition of sulfide or episulfide as a suffix. In this manner, 2 is named cycloocta-l,5-diene monoepisulfide. Alternatively, epithio can be used as a prefix, leading to the name epithio-2,5-dihydrofuran for 3 <1996CHEC-II(1)241>. 

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