Rutheniumkatalysierte Homokupplung von terminalen Alkinen

Conversion of 3,3,3-Trisubstituted Prop-1-ynes with tert-Butylhydrazine into 3,3,3-Trisubstituted Propionitriles Catalyzed by TpRh(C2H4)2/P(2-furyl)3

“…The catalytic cycle involves the formation of a vinylideneruthenium complex, followed by the nucleophilic attack of a hydrazine nitrogen at the α-carbon of the vinylidene ligand. − While primary and secondary alkyl- and aryl-substituted alkynes were applicable to the reaction, the reaction of tertiary alkyl-substituted alkynes such as tert -butylacetylene under the same reaction conditions afforded dimerization products derived from alkynes and not nitriles. The latter type of reaction was also reported by Kirchner and co-workers, and a vinylideneruthenium complex was proposed as an active precursor …”

Addition of Acetylenes to Olefins. Oxidative Coupling versus [2+2] Cycloaddition to a Vinylidene Intermediate

“…When the reaction of 1 with HC⋮CPh (3 equiv) is run in the absence of base, complexes 2a and 2b are obtained in 56 and 15% isolated yield. However, NMR monitoring of the progress of this reaction indicated complete consumption of 1 after 1 h, giving 2a and 2b in 3.3:1.0 ratio, with no evidence found for the formation of 2c but small amounts of polymeric materials (Table ) . The coupling reaction turned out to be not restricted to terminal alkynes.…”

Metal Vinylidenes and Allenylidenes in Catalysis: Applications in Anti‐Markovnikov Additions to Terminal Alkynes and Alkene Metathesis

“…A variety of ruthenium complexes containing trispyrazolyl, [131][132][133][134] P(CH 2 CH 2 PR 2 ) 3 , [126,127] N(CH 2 CH 2 PR 2 ) 3 , [135] pentamethylcyclopentadienyl, [136] indenyl, [137,138] and maltolato ligands, [139] the metathesis catalysts [RuCl 2 (PCy 3 ) 2 -(=CHPh)] [140] and [RuCl 2 (PiPr 3 ) 2 (=C=CHPh)], [141,142] as well as a dinuclear (C 5 H 5 ) 2 Ru 2 complex [143] promote the formation of Z and E enynes. Polyaddition of 2,7-diethynyl-9,9-dioctylfluorene with [RuCl 2 (PiPr 3 ) 2 ( = C = CHPh)] in the presence of N-methylpyrrolidine produces polymers containing the enynyl fragment with high Z selectivity.…”