排序方式: 共有16条查询结果,搜索用时 31 毫秒
1.
Reaction of 2-(vinyloxy)ethylisothiocyanate with unsaturated carbanions generated in situ from propargyl ethers and amines when treated with superbases, after S-alkylation and cyclization of the adducts in the presence of CuBr, leads to the previously unknown 2,3,5-substituted 1-[2-(vinyloxy)ethyl]pyrroles. 相似文献
2.
Reactions of 2-alkynyl arylethynyl selenide 1 with alkyl iodides 3 in the presence of lithium aluminium hydride via allenyl selenoketene 2 afforded cyclobutene 4. Allenyl group of the intermediate allenyl selenoketene 2 was monitored by React IR. 相似文献
3.
Animesh Roy Maximilian A. Silvestri Robert A. Hall Salvatore D. Lepore 《Tetrahedron letters》2017,58(1):106-108
In the attempt to synthesize substituted allenyl esters through a metathesis coupling of unsubstituted allenyl esters and alkenes using a variety of ruthenium catalysts, it was discovered that allenyl esters themselves cleanly arrested the activity of the catalysts. Further studies suggests possible utility of allene esters as general quenching agents for metathesis reactions. To explore this idea, several representative olefin metathesis reactions, including ring closing, were successfully terminated by the addition of simple allenyl esters for more convenient purification. 相似文献
4.
Adriano Boni Tiziana Funaioli Guido Pampaloni Stefano Zacchini 《Journal of organometallic chemistry》2011,696(22):3551-3556
The dimetallacyclopentenone complexes [Fe2Cp2(CO)(μ−CO){μ−η1:η3−CαHCβ(R)C(O)}] (R = CH2OH, 1a; R = CMe2OH, 1b; R = Ph, 1c) were prepared by photolytic reaction of [Fe2Cp2(CO)4] with alkyne according to the literature procedure. The X-ray and the electrochemical characterization of 1c are presented. The μ-allenyl compound [Fe2Cp2(CO)2(μ−CO){μ−η1:η2α,β−CαHCβCMe2][BF4] ([2][BF4]), obtained by reaction of 1b with HBF4, underwent monoelectron reduction to give a radical species which was detected by EPR at room temperature. The EPR signal has been assigned to [Fe2Cp2(CO)2(μ−CO){μ−η1:η2α,β-CαHCβCMe2}], [2]•. The molecular structures of [2]+ and [2]• were optimized by DFT calculations. The unpaired electron in [2]• is localized mainly at the metal centers and, coherently, [2]• does not undergo carbon-carbon dimerization, by contrast with what previously observed for the μ-vinyl radical complex [Fe2Cp2(CO)2(μ−CO){μ−η1:η2-CHCH(Ph)}]•, [3]•. Electron spin density distributions similar to the one of [2]• were found for the μ-allenyl radical complexes [Fe2Cp2(CO)2(μ-CO){μ-η1:η2α,β-CαHCβC(R1)(R2)}]• (R1 = R2 = H, [4]•; R1 = H, R2 = Ph, [5]•; R1 = R2 = Ph, [6]•). 相似文献
5.
Selby A.R. Knox 《Journal of organometallic chemistry》2007,692(19):4119-4128
The diruthenium μ-allenyl complex [Ru2(CO)(NCMe)(μ-CO){μ-η1:η2-C(H)CC(Me)(Ph)}(Cp)2][BF4], 3b, reacts with halide anions to yield the neutral derivatives [Ru2(CO)2(X){μ-η1:η2-C(H)CC(Me)(Ph)}(Cp)2] [X = Cl, 4b; X = Br, 4c; X = I, 4d]. Complex 4b undergoes isomerization to the unprecedented bridging vinyl-chlorocarbene species [Ru2(CO)(μ-CO){μ-η1:η3- C(Cl)C(H)C(Me)(Ph)}(Cp)2], 10, upon filtration of a CH2Cl2 solution through an alumina column.Complex 3b reacts with an excess of NaBH4 to give five products: the allene complex [Ru2(CO)2{μ-η2:η2- CH2CC(Me)(Ph)}(Cp)2], 5; the hydride species trans-[Ru2(CO)2(μ-H){μ-η1:η2-CHCC(Me)(Ph)}(Cp)2], 6, and cis-[Ru2(CO)2(μ-H){μ-η1:η2-CHCC(Me)(Ph)}(Cp)2], 8; the vinyl-alkylidene [Ru2(CO)(μ-CO){μ-η1:η3- C(H)C(H)C(Me)(Ph)}(Cp)2], 9; and the cluster [Ru3(CO)3(μ-H)3(Cp)3], 7.Studies on the thermal stabilities of 5, 6, 8 and 9 have suggested a plausible mechanism for the formation of these complexes and for the synthesis of 10. 相似文献
6.
Fu-Yu Tsai Ray-Hsi Hsu Tsang-Miao Huang Jwu-Ting Chen Gene-Hsiang Lee Yu Wang 《Journal of organometallic chemistry》1996,520(1-2):85-96
Regioselective addition of chalcogenol to an ν3-propargyl complex Pt(PPh3)2(η3-C3H3)](BF4) (2) via the formation of the C---O, C---S, or C---Se bond generates new cationic chalcogenoxyallyl species {Pt(PPh3)2[η3CH2C(ER)CH2]}(BF4) (E = O, R = Me 4(a), Et (4b, iPr (4c), 1Bu (4d), Ph (4e); E=S, E=Et (5b), tBu (5d, Ph (5e); E=Se, R=Ph (6e )) respectively in good yields. Thiol and selenol react with complex 2 much faster than alcohol; and 2 reacts with p-(HO)C6H4(SH) to exclusively yield the thioxyallyl product {Pt(PPh3)2[η3-CH2C(SC6H4OH)CH2]}(BF4) (5f). Among the alcoh and phenol, thereactivity follows the order MeOH > EtOH >, iPrOH >, tBuOH > PhOH. A mechanism comprising a preceding coordination step is postulated. The X-ray structures of 4b, 4e, 5b, 5e and 6e are provided. 相似文献
7.
H.M. Sampath Kumar Parvinder Pal Singh Syed Shafi Pitta Bhaskar Reddy Kankala Shravankumar Doma Mahender Reddy 《Tetrahedron letters》2007,48(5):887-890
5-Butynylisoxazoles were obtained in high yields through a domino addition, C-O heterocyclization involving allenylmagnesium bromide and benzonitrile oxide in dry THF, in which the corresponding 5-methylisoxazoles were isolated in trace amounts. However, when the reactions were attempted in aqueous media using allenylindium bromide, 5-methylisoxazoles were formed as the sole products in high yields. 相似文献
8.
Allenic imidothioates, H2CCC(Ph)C(SMe)NR (R = Me, t-Bu, Ph) have been obtained in good yields by reaction of 1,3-dilithiated 1-(2-propynyl)benzene with isothiocyanates and successive addition of t-butyl alcohol and methyl iodide. Heating the imidothioates at ∼120 °C gave an iminocyclobutene as the only isolated product (if R = t-Bu), a ∼4:6 mixture of a 2,3-dihydropyridine and an iminocyclobutene (if R = Me) or a 3:1 mixture of a quinoline and an iminocyclobutene (if R = Ph). 相似文献
9.
The hydrochalcogenation of allenyl sulfones with sodium organyl chalcogenolates can proceed smoothly to give β‐phenylchalcogenyl allyl sulfones in high yields with exclusive regioselectivity. For the asymmetric allenyl sulfone, the reaction has both high regio‐ and stereoselectivity with the predominace of E‐isomer. Some applications of β‐phenyltelluro and β‐phenylselanyl allyl sulfone in organic synthesis are also investigated. 相似文献
10.
Shinji Kitagaki 《Tetrahedron》2010,66(21):3687-5333
The intramolecular trapping of allenyl/propargyl anions, generated from sulfonylallenes with the proper base, by a haloalkyl group or an aldehyde functionality was investigated. The treatment of 1-(ω-iodoalkyl)-1-(phenylsulfonyl)allenes with TBAF or NaH in DMF efficiently produced the 1-alkynyl-1-(phenylsulfonyl)-substituted three- to seven-membered carbocycles. The allenyl/propargyl anions could also be intramolecularly trapped using a terminal aldehyde to stereoselectively afford the 2-alkynyl-2-(phenylsulfonyl)-substituted five- and six-membered cycloalkanols. The latter reaction could be performed using a catalytic amount of TBAF or DBU. 相似文献