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8.8- Dicyanoheptafulvene

In addition to 534, further [4+2]-cycloadducts of 5 were prepared by using 1,3-dienes, some of which are well known as trapping reagents of short-lived cyclic allenes and cycloalkynes. Further, cycloadditions could be achieved with tropone and several 2-substituted tropones, 8,8-dicyanoheptafulvene, 1,3,5-cycloheptatriene and a few of its 7-substituted derivatives. The products of these reactions are represented in Scheme 6.108. [Pg.339]

Scheme 6.108 Products ofthe interception of 1,2,4,6-cyclohepta-tetraene (5) with 1,3-diphenylisobenzofuran, anthracenes, 2,5-dimethyl-3,4-diphenylcyclopenta-2,4-dien-l-one, methyl 2-pyrone-5-carboxylate, tropones, 8,8-dicyanoheptafulvene and 1,3,5-cycloheptatrienes. Scheme 6.108 Products ofthe interception of 1,2,4,6-cyclohepta-tetraene (5) with 1,3-diphenylisobenzofuran, anthracenes, 2,5-dimethyl-3,4-diphenylcyclopenta-2,4-dien-l-one, methyl 2-pyrone-5-carboxylate, tropones, 8,8-dicyanoheptafulvene and 1,3,5-cycloheptatrienes.
SYNTHESIS OF 8,8-DICYANOHEPTAFULVENE FROM CYCLOHEPTATRIENYLIUM TETRAFLUOROBORATE AND BROMOMALONONITRILE... [Pg.106]

Dicyanoheptafulvene 2,4,6-Cycloheptatriene-A1 -malononitrile (8) Propanedinitrile, 2,4,6-cycloheptatrien-1-ylidene- (9) (2860-54-0) Cycloheptatrienylium tetrafluoroborate Aldrich Tropylium tetrafluoroborate Cycloheptatrienylium, tetrafluoroborate (1-) (8,9) (27081-10-3) Bromomalononitrile, Malononitrile, bromo- (8) Propanedinitrile, bromo- (8) (1885-22-9)... [Pg.108]

Volume 75 concludes with six procedures for the preparation of valuable building blocks. The first, 6,7-DIHYDROCYCLOPENTA-l,3-DIOXIN-5(4H)-ONE, serves as an effective /3-keto vinyl cation equivalent when subjected to reductive and alkylative 1,3-carbonyl transpositions. 3-CYCLOPENTENE-l-CARBOXYLIC ACID, the second procedure in this series, is prepared via the reaction of dimethyl malonate and cis-l,4-dichloro-2-butene, followed by hydrolysis and decarboxylation. The use of tetrahaloarenes as diaryne equivalents for the potential construction of molecular belts, collars, and strips is demonstrated with the preparation of anti- and syn-l,4,5,8-TETRAHYDROANTHRACENE 1,4 5,8-DIEPOXIDES. Also of potential interest to the organic materials community is 8,8-DICYANOHEPTAFULVENE, prepared by the condensation of cycloheptatrienylium tetrafluoroborate with bromomalononitrile. The preparation of 2-PHENYL-l-PYRROLINE, an important heterocycle for the synthesis of a variety of alkaloids and pyrroloisoquinoline antidepressants, illustrates the utility of the inexpensive N-vinylpyrrolidin-2-one as an effective 3-aminopropyl carbanion equivalent. The final preparation in Volume 75, cis-4a(S), 8a(R)-PERHYDRO-6(2H)-ISOQUINOLINONES, il lustrates the conversion of quinine via oxidative degradation to meroquinene esters that are subsequently cyclized to N-acylated cis-perhydroisoquinolones and as such represent attractive building blocks now readily available in the pool of chiral substrates. [Pg.140]

The present procedure emphasizes pyridine as the solvent with mild heating. When pyridine is partially replaced with acetonitrile, the yield of 8,8-dicyanoheptafulvene, 2, drops to less than 40%. [Pg.254]

Cycloadditions of compound (128) with 6,6-diphenylfulvene, 8,8-dicyanoheptafulvene and tropone have also been reported (81CL213). [Pg.1041]

Synthesis of 8,8-Dicyanoheptafulvene from Cycloheplatrienylium Tetraftuoroborate and Bromomalononitrile. [Pg.265]

Oxa-thiacrown ethers containing 8,8-dicyanoheptafulvene units <1995CL629, 1995H(49)385, 2000AXC644> were prepared by Takeshita and co-workers. Compounds 81, 82, 83a, and 83b have been prepared and their HgCl2 complexes have been investigated. [Pg.840]

Dicyanoheptafulvene has been made from tropyliom bromide [359], tropone [369] or alkoxy- [94,369] or chloro-tropylium salts [370], and malononitrile. It is a stable red solid and does not react with dienophiles or with electrophiles under normal conditions. It will, however, add bromine under the influence of light [371]. [Pg.296]

X-ray studies show 8,8-dicyanoheptafulvene to be approximately planar but with notably alternating bond lengths [372]. Nevertheless it has a large dipole moment (7.49 D) [373]. Introduction of methyl groups at the 2,7-positions results in the ring taking up a non-planar boat form, presumably because of strong intramolecular interaction between the 2,7 and 1(8) substituents [374]. [Pg.296]

C9Hi8BrN02, 1-Aminocyclooctane carboxylic acid hydrobromide, 37B, 82 CioHeN2f 8,8-Dicyanoheptafulvene, 31B, 91... [Pg.75]

Ikuno and coworkers [73] studied the reaction of 4-methoxybenzenamine 287 and l,2,3,4-tetrahydro-l,3,6-trimethyl-2,4-dioxopyrimidine-5-carbaldehyde 288 with 8,8-dicyanoheptafulvene 259, which yields tetrahydrocyclo-hepta[ ]quinazoline 289 (Scheme 7.63). [Pg.283]


See other pages where 8.8- Dicyanoheptafulvene is mentioned: [Pg.107]    [Pg.107]    [Pg.124]    [Pg.253]    [Pg.121]    [Pg.211]    [Pg.212]    [Pg.212]    [Pg.236]    [Pg.841]    [Pg.135]    [Pg.405]    [Pg.490]    [Pg.72]    [Pg.66]    [Pg.183]    [Pg.183]    [Pg.513]    [Pg.75]    [Pg.75]    [Pg.280]    [Pg.240]   
See also in sourсe #XX -- [ Pg.236 ]




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8.8- DICYANOHEPTAFULVENE: 2,4,6-CYCLOHEPTATRIENE

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