ethinyloges 1‐Benzyl‐1,2‐dihydroisochinolin sollte 7 mit verdünnter Säure die Dihydroisochinolinumlagerung erleiden. Mit verdünnter HCl entstand aus 7 ein Gemisch von Umlagerungsprodukten, das nicht getrennt werden konnte. Die Ergebnisse von spektroskopischen Untersuchungen sprechen dafür, daß 7 die erwartete Dihydroisochinolinumlagerung erfahren hat.
Enantioselective Synthesis of 4-Hydroxy-2-cyclohexenones through a Multicomponent Cyclization
作者:José Barluenga、Marcos G. Suero、Raquel De la Campa、Josefa Flórez
DOI:10.1002/anie.201004413
日期:2010.12.10
and a propargylic organomagnesium reagent giving access to novel and densely functionalized 4‐allenyl‐2‐cyclohexenones (see scheme). These useful synthetic intermediates have been prepared through a cyclization process that involves newly reported reaction steps and an unusually high level of asymmetric induction.
Gold‐Catalyzed Cyclizations and [3+2]‐Annulation Cascades between 1,5‐Diyn‐3‐ols and Nitrones to Construct Carbazole Frameworks
作者:Sudhakar Dattatray Tanpure、Manoj Dilip Dhole、Rai‐Shung Liu
DOI:10.1002/adsc.202300711
日期:2023.9.5
Gold-catalyzedcascade reactions between 1,5-diyn-3-ols and nitrones to deliver carbazole derivatives are described. Such cascade reactions are applicable to facile synthesis of polyaromatic compounds containing carbazole subunits. Notably, the reaction mechanism involves unexpected oxoarylations, rather than oxidative Mannich reactions as known for but-1-yn-4-ols. Our control experiments indicate
Synthesis and Electronic Structure of Tetrakis(η<sup>3</sup>-phenylpropargyl)zirconium
作者:Dan R. Denomme、Seth M. Dumbris、I. F. Dempsey Hyatt、Khalil A. Abboud、Ion Ghiviriga、Lisa McElwee-White
DOI:10.1021/om100405n
日期:2010.11.8
Tetrakis(eta(3)-phenylpropargyl)zirconium (3) was synthesized from ZrCl4 and (phenylpropargyl)magnesium bromide. The crystallographically determined structure of 3 exhibits D-2d symmetry, consistent with the H-1 and C-13 NMR spectra. The electronic structure of 3 was analyzed using DFT calculations, and a HOMO - LUMO gap of 5.3 eV was calculated. The eta(3) coordination of the propargyl ligands and steric hindrance around the Zr center prevent the coordination of additional ligands, resulting in a homoleptic complex.
Cyclization Accompanied with 1,2-Phenyl Migration in the Protonation of Ruthenium Acetylide Complex Containing an Allenyl Group
作者:Kuo-Hao Chen、Yi Jhen Feng、Hao-Wei Ma、Ying-Chih Lin、Yi-Hong Liu、Ting-Shen Kuo
DOI:10.1021/om101017p
日期:2010.12.27
Reaction of the ruthenium allenylidene complex [Ru]=C=CPh2 (1 [Ru] = Cp(PPh3)(2)Ru) with the propargylic Grignard reagent R C CCH2MgBr (R = CH3 CH2CH3 Ph) yielded a mixture of two acetylide complexes The major products [Ru]C CCPh2C(R)=C=CH2 (2a R = CH3 2b R = CH2CH3 2c R = Ph) have an allenyne moiety and the minor ones [Ru]C CCPh2CH2C CR (3a R = CH3 3h R = CH2CH3 3c R = Ph) have a diyne ligand The reaction of similar propargyl Grignard reagent HC CCH2MgBr with 1 yielded only the diyne complex 3d Treatment of complexes 2a-2c with HBF4 afforded the cyclization complexes 5a-5c respectively proceeding via a vinylidene intermediate The cyclization of the allenyl and the vinylidene groups is accompanied with a phenyl group migration Complex 5b is fully characterized by a single-crystal X ray diffraction analysis Similar cyclization of complexes 2a and 2b catalyzed by a Au phosphine complex gave the ruthenium vinylidene complexes 6a and 6b respectively with different selectivity from that of the protonation reaction Au catalyzed cyclization of the diyne complex 3d yielded 6d which is fully characterized by a single crystal X ray diffraction analysis