1608-10-2Relevant articles and documents
REGIOSELECTIVE CARBON-CARBON BOND FORMATION BY REACTION OF Zr-ISOPRENE COMPLEX WITH ALKENES, ALKYNES AND ALKADIENES
Yasuda, Hajime,Kajihara, Yasushi,Nagasuna, Kinya,Mashima, Kazushi,Nakamura, Akira
, p. 719 - 722 (1981)
The reaction of ZrCp2(isoprene) with 1-butene, 2-butene, 1-pentene and 2-pentene proceeds with highly regioselective carbon-carbon bond formation between C2-carbon of alkenes and C4-carbon of isoprene unit.In the presence of excess isoprene, the Zr-complex showed catalysis for selective tail-to-tail linear dimerization of isoprene.The addition of diphenylacetylene resulted in the release of isoprene to form a zirconacyclo-2,4-pentadiene.
Selective preparation of 1,3-butadienyl phosphines, 1-iodo- and 1,4-diiodo-butadienyl phosphine oxides via zirconocene-mediated cross-coupling of alkynylphosphines
Xi, Zhenfeng,Zhang, Wenxiong,Takahashi, Tamotsu
, p. 2427 - 2429 (2004)
Stereodefined butadienyl phosphines and related derivatives were readily prepared in high yields with perfect regioselectivity via the zirconocene-mediated pair-selective coupling of alkynylphosphines with ethylene or alkynylphosphines with normal alkynes
Efficient blue emission from siloles
Tang,Zhan,Yu,Lee,Liu,Zhu
, p. 2974 - 2978 (2001)
2,3,4,5-Tetraphenylsiloles with different 1,1-substituents on the ring silicon atoms, i.e., 1,1-dimethyl-2,3,4,5-tetraphenylsilole (1), 1-methyl-l-(3-chloropropyl)-2,3,4,5-tetraphenylsilole (2), 1-methyl-l,2,3,4,5-pentaphenylsilole (3) and hexaphenylsilol
A FACILE HIGH-YIELD SYNTHESIS OF DI-η5-CYCLOPENTADIENYLHAFNACYCLOPENTADIENE COMPOUNDS
Sabade, Milind B.,Farona, Michael F.
, p. 311 - 316 (1986)
Hafnocene dichloride was reduced with amalgamated magnesium in the presence of alkynes giving high yields of di-η5-cyclopentadienylhafnacyclopentadienes.Reaction with hydrochloric acid yields exclusively the corresponding (E,E)-butadiene deriva
Stereoselective and Stereospecific Reactions of Cobalt Sandwich Complexes: Synthesis of a New Class of Single Enantiomer Bulky Planar Chiral P?N and P?P Ligands
Arthurs, Ross A.,Horton, Peter N.,Coles, Simon J.,Richards, Christopher J.
, p. 4310 - 4319 (2018)
Starting from (η5-acetylcyclopentadienyl)(η4-tetraphenylcyclobutadiene)cobalt(I), highly enantioselective (99 % ee) (S)-CBS catalysed ketone reduction followed by stereospecific alcohol-azide exchange, azide reduction and dimethyllation gave (R)-(η5-α-N,N-dimethylaminoethylcyclopentadienyl)(η4-tetraphenylcyclobutadiene) cobalt(I) (Arthurs’ amine). This underwent highly diastereoselective cyclopalladation to give di-μ-acetate-bis-(R)-[(η5-(Sp)-2-(α-N,N-dimethylaminoethyl)cyclopentadienyl, 1-C, N)(η4-tetraphenylcyclobutadiene)cobalt(I)]dipalladium, and highly diastereoselective lithiation to give (R)-(η5-(Sp)-1-(α-N,N-dimethylaminoethyl)-2-(diphenylphosphino)cyclopentadienyl)(η4-tetraphenylcyclobutadiene)cobalt(I) (PPCA) following the addition as electrophile of chlorodiphenylphosphine. This PN-ligand was converted into (R)-(η5-(Sp)-1-(α-dicyclohexylphosphinoethyl)-2-(diphenylphosphino)cyclopentadienyl)(η4-tetraphenylcyclobutadiene)cobalt(I), a PP-ligand (Rossiphos), by stereospecific amine-phosphine exchange using HPCy2. These air-stable P?N and P?P complexes are the first examples of a new class of bulky planar chiral ligands for application in asymmetric catalysis.
The crystal structure of [Mo(NCS)(CO)2(η3-C3H5) (NCMe)2].MeCN and the reactions of {Mo(CO)2 (η3-C3H5)+} containing species with symmetric alkynes
Goodyear, Jonathan W.,Hemingway, Clive W.,Harrington, Ross W.,Wisemann, Matthew R.,Brisdon, Brian J.
, p. 176 - 181 (2002)
In the solid-state about molybdenum, with carbonyls and nitriles in the equatorial plane and an N-bonded thiocyanate group trans to the allyl ligand. In refluxing methanol or acetonitrile both 1, and the analogous chloro-complex [MoCl(CO)2(η3-C3 H5)(NCMe)2](2) catalytically convert PhC≡CPh to a mixture of hexaphenylbenzene and E,E-1,2,3,4-tetraphenylbutadiene. By contrast MeO2CC≡CCO2Me is not oligomerised. In methanol, complex 2 dimerises 1,4-diphenylbutadiyne to Z,E-1,4,5,8-tetraphenyl-1,7-octa-3,5-diene-1,7-diyne, whereas in the presence of base both the complex and the diyne, react preferentially with the solvent to generate the [Mo2(CO)4 (η3-C3H5)2 (OMe)3]- anion and Z-1,4-diphenyl-3- methoxy-but-3-ene-1-yne, respectively.
Aggregation-induced emission of cis,cis-1,2,3,4-tetraphenylbutadiene from restricted intramolecular rotation
Chen, Junwu,Xu, Bin,Ouyang, Xiaoying,Tang, Ben Zhong,Cao, Yong
, p. 7522 - 7526 (2004)
cis,cis-1,2,3,4-Tetraphenylbutadiene (TPBD) exhibits aggregation-induced emission (AIE) in the UV-blue band: the photoluminescence (PL) quantum yield of TPBD aggregates can differ from that of molecularly dissolved species by 2 orders of magnitude (>200).
Rare-Earth Supported Nickel Catalysts for Alkyne Semihydrogenation: Chemo- And Regioselectivity Impacted by the Lewis Acidity and Size of the Support
Ramirez, Bianca L.,Lu, Connie C.
supporting information, p. 5396 - 5407 (2020/04/09)
Bimetallic catalysts of nickel(0) with a trivalent rare-earth ion or Ga(III), NiML3 (where L is [iPr2PCH2NPh]-, and M is Sc, Y, La, Lu, or Ga), were investigated for the selective hydrogenation of diphenylacetylene (DPA) to (E)-stilbene. Each bimetallic complex features a relatively short Ni-M bond length, ranging from 2.3395(8) ? (Ni-Ga) to 2.5732(4) ? (Ni-La). The anodic peak potentials of the NiML3 complexes vary from -0.48 V to -1.23 V, where the potentials are negatively correlated with the Lewis acidity of the M(III) ion. Three catalysts, Ni-Y, Ni-Lu, and Ni-Ga, showed nearly quantitative conversions in the semihydrogenation of DPA, with NiYL3 giving the highest selectivity for (E)-stilbene. Initial rate studies were performed on the two tandem catalytic reactions: DPA hydrogenation and (Z)-stilbene isomerization. The catalytic activity in DPA hydrogenation follows the order Ni-Ga > Ni-La > Ni-Y > Ni-Lu > Ni-Sc. The ranking of catalysts by (Z)-stilbene isomerization initial rates is Ni-Ga ? Ni-Sc > Ni-Lu > Ni-Y > Ni-La. In operando 31P and 1H NMR studies revealed that in the presence of DPA, the Ni bimetallic complexes supported by Y, Lu, and La form the Ni(η2-alkyne) intermediate, (η2-PhCCPh)Ni(iPr2PCH2NPh)2M(κ2-iPr2PCH2NPh). In contrast, the Ni-Ga resting state is the Ni(η2-H2) species, and Ni-Sc showed no detectable binding of either substrate. Hence, the mechanism of Ni-catalyzed diphenylacetylene semihydrogenation adheres to two different kinetics: an autotandem pathway (Ni-Ga, Ni-Sc) versus temporally separated tandem reactions (Ni-Y, Ni-Lu, Ni-La). Collectively, the experimental results demonstrate that modulating a base-metal center via a covalently appended Lewis acidic support is viable for promoting selective alkyne semihydrogenation.
Nickel-Catalyzed Reductive [2+2] Cycloaddition of Alkynes
Ca?ellas, Santiago,Montgomery, John,Pericàs, Miquel à.
supporting information, p. 17349 - 17355 (2019/01/04)
The nickel-catalyzed synthesis of tetrasubstituted cyclobutenes from alkynes is reported. This transformation is uniquely promoted by the use of a primary aminophosphine, an unusual ligand in nickel catalysis. Mechanistic insights for this new transformation are provided, and postreaction modifications of the cyclobutene products to stereodefined cyclic and acyclic compounds are reported, including the synthesis of epi-truxillic acid.
Ni-Catalyzed Dimerization and Arylation of Diarylacetylenes with Arylboronic Acids
Liu, Yang,Zhang, Guoying,Huang, Hanmin
supporting information, p. 6674 - 6677 (2017/12/26)
A new, facile, and efficient protocol for the synthesis of polysubstituted conjugated 1,3-dienes through Ni-catalyzed tandem dimerization/cross-coupling reaction of diarylacetylenes and arylboronic acids in the presence of a catalytic amount of B2pin2 has been developed. A series of arynes and arylboronic acids with different substituents participated well in this catalytic system, affording a variety of useful conjugated 1,3-dienes.
