35286-95-4Relevant articles and documents
Chemoselective Cobalt(I)-Catalyzed Cyclotrimerization of (Un)Symmetrical 1,3-Butadiynes for the Synthesis of 1,2,4-Regioisomers
Weber, Sebastian M.,Hilt, Gerhard
, p. 4106 - 4110 (2019)
The cobalt(I)-catalyzed cyclotrimerization of (un)symmetrical 1,4-disubstituted 1,3-butadiynes is presented. In the case of unsymmetrical 1,3-butadiynes, this reaction can generate eight 1,2,4-substituted and four 1,3,5-substituted isomers. A single 1,2,4-substituted isomer was formed in excellent yields (up to 99%) and exclusive regioselectivities (>99:1) when symmetrical or a 1,3-butadiyne with an aryl or alkyl substituent and a trimethylsilyl group were applied. A large number of products accepting a wide variety of functional groups were synthesized.
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Tillack,Pulst,Baumann,Baudisch,Kortus,Rosenthal
, p. 117 - 123 (2007/10/03)
The hydrosilatation of nPr-C≡C-nPr, Ph-C≡C-Ph, Me3Si-C≡C-SiMe3, Ph-C≡C-C≡C-Ph, tBu-C≡C-C≡C-tBu and Me3Si-C≡C-C≡C-SiMe3 with Ph2SiH2, PhMe2SiH and Et3SiH in the presence of L2Ni(0)-butadiyne catalysts [L = Ph3P, (o-Tol-O)3P] has been studied. In all cases the hydrosilylation proceeds via a via a cis-addition of the silanes. The disubstituted alkynes (nPr-C≡C-nPr, Ph-C≡C-Ph) give hydrosilylated ethene, butadiene and hexatriene derivatives as well as non-hydrosilylated benzene derivatives. In the case of Me3Si-C≡C-SiMe3 no reaction was observed. The hydrosilylation of disubstituted butadiynes proceeds stepwise to give at first the 1,2-adducts. In dependence on the butadiynes either a 1,4-addition (tBu-C≡C-C≡C-tBu, Me3Si-C≡C-C≡C-SiMe3) to the corresponding allene derivatives (11, 13, 15) or a 3,4-addition (Ph-C≡C-C≡C-Ph) to the 1,3-butadiene 19 takes place subsequently. The reaction products were characterized by mass spectrometry, IR and NMR spectroscopy.
