Buta-l,3-diynes

A modification of this method is known When a sodium telluride solution in ethanol at 30°C is treated with l,4-di(trimethylsilyl)buta-l,3-diyne for 3 h, the result is tellurophene in 84% yield (78CB3745). 

Reactions between [ppn][Au(acac)2] and buta-l,3-diyne give [ppn][Au(C= CC=CH)2]. Similarly, (AuCl)2(/U-dppm) affords Au(C=CC=CH)2 (ju-dppm) while serendipitous use of a stoichiometric amount of Cul catalyst resulted in migration of dppm from gold to copper and formation of the curious bis(diynyl) species Cu3(/U3-I)(/.i3-C=CC=CAuC=CC=CH)(/r -dppm)3 (31). Direct reaction between [ppn][Au(C CC=CH)2] and [Cu2(/L-dppm)2(NCMe)2]" " afforded the dumbbell complex 32. 

Cobalt carbonyl adducts of buta-l,3-diyne are best obtained via indirect methods. Very early work showed that the reaction between Hg Co(CO)4 2... 

An alternative route to cationic butatrienylidene complex 4 involves 1,4-H shift in butadiyne complex 9. The formation of 4 as an intermediate in the reaction of [Cp(PPh3)3Ru-Cl] with AgPFg and buta-l,3-diyne was deduced from trapping experiments. Complex 4 thus generated gave with diphenylamine the corresponding diphenylamino(methyl)allenylidene complex (Scheme 3.5) [19]. 

In 1972 Berry and co-worker detected 3,4-pyridyne (101) by MS. Trapping experiments also provided evidence for the existence of this intermediate, although the chemistry of 101 differs considerably from that of o-benzyne. Thus, neither anthracene nor dimethylfulvene form Diels-Alder adducts with 101. Nam and Leroi were able to generate 101 in nitrogen matrices at 13 K and characterized it by IR spectroscopy. Irradiation of 3,4-pyridinedicarboxylic anhydride (103) with 1 > 340 nm results in formation of 101, which upon short wavelength photolysis (k > 210 nm) fragments to buta-l,3-diyne (104) and HCN, and to acetylene (105) and cyanoacetylene (106, Scheme 16.24). The assignment of an intense... 

Although indolyl- and pyrrolyl-alkynes have been synthesized (see Section 3.05.2.5), their general thermal instability has precluded an examination of their chemical reactivity. 3-Indolylacetylene, however, has been shown to react with halogenoalkynes to produce in moderate yield the corresponding l-(3-indolyl)buta-l,3-diynes (80ZOR758). 

Bis(trimethyl silyl )buta-l,3-diyne 2,7-Disilaocta-3, 5-diyne,... 

Sometimes the triethylsilyl grouping is more suitable for poly-acetylene synthesis because of its greater stability, namely in the Cadiot-Chodkiewicz coupling reaction44 of a halogenoacetylene with unprotected l-phenyl-buta-l,3-diyne (39)... 

Irradiation of the trisilane system in the presence of l,4-bis(trimethylsilanyl)buta-l,3-diyne affords the as- and // ///Av-isomcnc l,3-dimethylene-2,4-disilacyclobutane derivatives, presumably via a 1-sila-allene intermediate (Equation 32) < 1999EJI2301 >. 

BIS(TRHCTHYLSILYL)BUTA-l, 3-DIYNE (Silane, 1,3-butadiyne-l, 4-diylbis[trimethyl-)... 

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