6231-26-1Relevant academic research and scientific papers
Can the Ti(OiPr)4/nBuLi combination of reagents function as a catalyst for [2+2+2] alkyne cyclotrimerisation reactions?
Siemiaszko, Gabriela,Six, Yvan
supporting information, p. 20219 - 20226 (2018/12/13)
Catalysis of the cyclotrimerisation of alkynes with the Ti(OiPr)4/nBuLi system was studied, leading to the development of a particularly convenient and reliable protocol. This method allows the [2+2+2] cycloaddition reaction to proceed within a few minutes under microwave conditions, with generally good selectivity from a variety of aromatic and aliphatic alkynes.
Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel
Islas, Rosa E.,García, Juventino J.
, p. 4125 - 4131 (2017/10/09)
The use of simple and inexpensive NiCl2?6 H2O as a catalyst precursor for C?P bond formation in the presence of commercially available trialkyl phosphites (P(OR)3, R=Et, iPr, Bu, SiMe3) along with several alkynes is presented. Control experiments showed the in situ formation of (RO)2P(O)H as the species that undergo the addition into the C≡C bond at the alkynes to yield the product of P?H addition. The hydrophosphonylation of diphenylacetylene with P(OEt)3, P(OiPr)3, and P(OSiMe3)3 proceeds in high yields (>92 %) without the need of a specific solvent or ligand. This method is useful for the preparation of organophosphonates for both phenylacetylene as a terminal alkyne model and internal alkynes in yields that range from good to modest.
Bis(acetylacetonato)Ni(II)/NaBHEt3-catalyzed hydrosilylation of 1,3-dienes, alkenes and alkynes
Srinivas, Venu,Nakajima, Yumiko,Ando, Wataru,Sato, Kazuhiko,Shimada, Shigeru
, p. 57 - 62 (2018/03/27)
The utility of commercially available Ni(II) salts, Ni(acac)2 (acac = acetylacetonato) (1a) and its derivatives bis(hexafluoroacetylacetonato)nickel(II) (1b) and bis(2,2,6,6-tetramethyl-3,5-heptanedionato)nickel(II) (1c) as versatile hydrosilylation catalyst precursors is described. Complexes 1a-c catalyze 1,4-selective hydrosilylation of 1,3-dienes in the presence of NaBHEt3 at ambient temperature. The reactions exhibit good regioselectivity to give the branched isomers as major products. The catalytic system also catalyzes hydrosilylation of alkenes including industriary important siloxy-, amino-, and epoxy-substituted ones as well as both terminal and internal alkynes.
Easily available nickel complexes as catalysts for the intermolecular hydroamination of alkenes and alkynes
Reyes-Sanchez, Adan,Garcia-Ventura, Ilnett,Garcia, Juventino J.
, p. 1762 - 1768 (2014/01/06)
A series of nickel complexes of the type [(P-P)NiX2] ((P-P) = bisphospines or bisphosphites, X = chloride, triflate) were used as catalysts for the hydroamination of both activated and unactivated alkenes and alkynes with pyrrolidine. In general, the use of activated unsaturations, such as acrylonitrile, required mild reaction conditions (e.g. 100 °C and 4 h) in comparison with other non-activated alkenes. Particularly with a series of alkynes, the use of nickel(ii) centers diminished or even inhibited the formation of otherwise undesired homocoupling and/or transfer hydrogenation by-products, such as the ones obtained in the presence of zerovalent nickel. When using less activated substrates, better selectivity was obtained, although harsher reaction conditions were needed. From a general perspective, the results of this report strongly support the potential use of nickel as a good candidate for further application in the hydroamination of organic unsaturations by means of screening of several π acceptor ligands. The Royal Society of Chemistry.
