Butadiyne preparation methods

Butadynyl and butadynediyl complexes bearing the FeCp (CO)2 (Fp ) terminus were prepared by conventional methods(scheme 1). Butadynyl complexes, Fp -CsC-CsC-H, were readily obtained by the alkynylation of Fp -I with Li-C C-CsC-SiMea, followed by desilylation. The Cu-catalyzed metalation of complex 2 with M-X (M =Fp, Rp) gave the butadiyne complexes 3. 

Compounds 32 could also be prepared by the reduction of Cp"2ZrCl2 with magnesium in the presence of the butadiynes RC=C C=CR (R = Me, Ph, SiMe3). The corresponding titanacyclocumulenes could not be prepared by either of the described methods. For... 

Oxidative coupling of terminal acetylenes in the presence of copper(I) catalysts is the best method of preparing symmetrically substituted butadiyne derivatives,5 and has been applied to the coupling of trimethylsilyl-acetylene. Better yields are obtained using the Hay procedure in which the catalyst is the TMEDA complex of copper(I) chloride.7 The procedure submitted here is an improved version of Walton and Waugh s synthesis of BTMSBD by the Hay coupling of trimethylsilylacetylene.2 BTMSBD has also been prepared by... 

Conjugated 1,3-butadiyne or longer oligoyne units are widespread structural motifs in many natural products [171] and novel functional materials [3, 167]. Their preparation is typically accompHshed by a metal-catalyzed cross-couphng of an alkynylcopper species to a haHde-terminated alkyne. While the catalytic system substantially relies on the use of Cu, the assistance of Pd is not mandatory. Either symmetric or nonsymmetric oligoynes can be made by this method, however. 

For some time, there has been interest in the controlled release properties of stabilized liposomes.(i-3) A number of methods for stabilizing liposomes have been developed. Liposomes have been prepared from lipids which contain polymerizable groups such as methacrylate, butadiyne, or diacetylene and subsequently polymerized.(4-6) Another strategy is to n e liposomes from lipids with amino add headgroups and then potymerize the liposome Ity potycondensatioiL(7) Alternatively, stabilized liposomes have been prepared from prepolymerized amphiphiles.(8) Recently, the design and preparation of... 

To prepare cyclic tetraynes consisting of 1,4-donor-substituted butadiyne units one can use the Glaser type coupling of terminal dithiadiynes 28(3) or 28(4) (Scheme 7.8). This method produces the 18- and 20-membered rings 29(3) and 29(4), respectively, but no trimerization products were found [40]. 

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