Diynes triynes

Alkynes contain one or more triple bonds. They are named in a similar way to alkenes. The suffix used for alkynes is -yne. Ethyne is often called acetylene. Alkynes with one triple bond have the general formula Cn 2n-2-Multiple triple bonds are named using -diyne, -triyne, etc. The infix -ynyl- is used for functional groups composed of alkynes after the removal of a hydrogen atom. 

Alkynes are named in a manner nearly identical to the naming of alkenes except that the suffix is -yne. The same rules for numbering apply. Compounds with several triple bonds use the suffixes -diyne, -triyne, and so on. For compounds that contain both a double bond and a triple bond, both suffixes are used, as in -enyne. Some examples follow ... 

Compounds with more than one triple bond are called diynes, triynes, and so forth compounds containing both double and triple bonds are called enynes (not ynenes). Numbering of an enyne chain starts from the end nearer the first multiple bond, whether double or triple. When there is a choiit in numbering, double bonds receive lower numbers than triple bonds. Fur example ... 

Okada, S., Hayamizu, K., Matsuda, H., Masaki, A., and Nakanishi, H., Structures of the polymers obtained by the solid-state polymerization of diyne, triyne, and tetrayne with long-alkyl substituents, Bull. Chem. Soc. Jpn., 64, 857, 1991. 

The terminal diyne 320 is prepared by coupling of the zinc acetylide 318 with /rfln.s-l-iodo-2-chloroethylenc (319), followed by elimination of HCI with sodium amide[231]. Similarly, terminal di- and triynes are prepared by using cw-l,2-dichloroethylene[232]. The 1-alkenyl or l-aryl-2-(perefluoroalkyl) acetylene 321 is prepared by the reaction of a zinc acetylide with halides[233]. 

Diynes and triynes refer to alkynes containing two or three triple bonds poly-ynes contain multiple triple bonds. A conjugated triyne is a straight-chain hydrocarbon with triple bonds alternating with single bonds. An examples is... 

Notice that an is used to indicate the absence of a double bond or triple bond, such as in pentane above. If there are two double bonds in a compound, then the unsaturation is -dien-. Three double bonds is -trien-. Similarly, two triple bonds is -diyn-, and three triple bonds is -triyn-. For multiple double and triple bonds, we use the following terms ... 

In order to minimize the formation of side products, PAM 4 can be assembled via an intramolecular approach [23]. The Sonogashira protocol [15] and conversion of masked iodides [24] comprises most of the chemistry involved in Scheme 7. Using these proven methods, diyne 16 and subsequently triyne 17 can be prepared quickly. lodination, desilylation, and intramolecular alkynylation with Pd(dba)2 under high dilution conditions furnished 4 as the sole product. 

Occurring Acetylene Compounds. XXVII. The Synthesis of a Mixture of Trideca-1.3,1l-triene-5,7,9-triyne (II) and trans-l-Phenylhepta-l,3-diyn-5-ene (V). A Novel Cyclisation Reaction. Acta Chem. Scand. 13, 2101 (1959). 

A variety of palladium-catalyzed dimerizations of conjugated enynes and their additions to diynes and triynes gave rise to styrene and phenylacetylene derivatives, respectively. Inter alia, 1,2,4-cyclohexatrienes have been invoked as intermediates in these reactions [134], 5,6-Diphenyl-l,2,4-cyclohexatriene has been proposed as an intermediate in the rearrangement of 4,4-diphenylcyclohexa-2,5-dienylidene to o-ter-phenyl and its possible existence was supported by quantum-chemical calculations [135],... 

Dimethyl-l-butyne, 2408 1,8-Diphenyloctatetrayne, 3788 Hepta-l,3,5-triyne, 2641 l-Heptene-4,6-diyne, 2707... 

In the contrast to the SiCaT reaction of triynes vide supra), when an enediyne has an olefin at the terminal position a novel silicon-initiated carbonylative carbotricyclization (CO-SiCaT) reaction takes place, incorporating CO into the product [52], As Scheme 7.24 indicates, the reaction of dodec-ll-ene-l,6-diynes 82 catalyzed by Rh(acac)(CO)2 under 1 atm. CO affords the corresponding cyclopenta[e]azulenes 83 in good to excellent yield. 

Several nematicidal acetylenic compounds have been isolated. Most are from the Asteraceae (127). Recently isolated are (8R,9R, 10S)-9,10-epoxyheptadec-16-ene-4,6-diyne-8-ol and other compounds from Cirsium. iaponicum (128,129). 1-Phenylhepta-l,3,5-triyne and 2-phehyl-5-(1 -jjropynyl)-thiopene, from Coreopsis lanceolata and cis-dehydromatricaria ester from Soli dago altissima have been shown to be fly ovicidal substances (130,131). 

Cascade silylcarbocyclization of (E)- or (Z)-dodec-6-ene-l,ll-diyne (355) with HSiMe2Ph catalyzed by Rh(acac)(CO)2 gives the bis(exo-methylenecyclopentyl) (356) with complete stereospecificity (equation 144)342. The reaction of dodec-l,6,ll-triyne (357) under the same conditions affords a 3 1 mixture of 358 and 359 in 75% yield... 

Acetylenes R-OC-R and higher oligomers, such as diynes R-(OC)2-R triynes R-(CsC)3-R, and tetraynes R-(C=C)4-R, have the requisite conjugation required for both %(2) and effects. With suitable substitution patterns, R = n-... 

The isochroman 604 is capable of DNA cleavage and can be accessed via a poor yielding cycloaromatization of the 10-membered cyclic diyne 605 (Equation 247) <1996TL2433>. A rhodium- or mthenium-catalyzed [2+2+2] cyclization of the triyne 606 can be used to construct the tricyclic isochroman 607 in excellent yield (Equation 248) <2003JA7784, 2003JA12143>. 

Intramolecular [2+2+2] cyclotrimerizations of diynes and triynes possessing heteroatom tethers furnish benzoheterocycles. The cyclization of triynes 88 using the Grubbs catalyst 76 proceeds via cascade metathesis as shown in Eq. (35) to yield a tricyclic product 89 [88]. This novel type of catalytic alkyne cyclotrimerization can be applied to the cycloaddition of 1,6-diynes with monoalkynes [89]. 

In previous works this group had observed a competition between the PKR and a [2 + 2 + 2] cyclization in the second reaction step of three triple bonds. Thus, when reacting linear triynes 174 under catalytic, high CO pressure, cobalt mediated PKR conditions, they obtained mixtures of products 175 coming from two [2 + 2 + 1] cycloadditions, and 176 from a [2 + 2 + 1]/ [2 + 2 + 2] tandem reaction. When the triple bonds were ether linked, the latter was the favored reaction, while with substrates lacking oxygen atoms, the iterative PKRs was the major pathway (Scheme 51) [166]. When the reaction was performed intramolecularly between a diyne and an alkyne, the only reaction products were the result of a [2 + 2 + 1 ]/[2 + 2 + 2] tandem cycloaddition [167,168]. 

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