30928-55-3Relevant academic research and scientific papers
Ruthenabenzene: A Robust Precatalyst
Gupta, Saswata,Su, Siyuan,Zhang, Yu,Liu, Peng,Wink, Donald J.,Lee, Daesung
supporting information, p. 7490 - 7500 (2021/05/26)
Metallaaromatics constitute a unique class of aromatic compounds where one or more transition metal elements are incorporated into the aromatic system, the parent of which is metallabenzene. One of the main concerns about metallabenzenes generally deals with the structural characterization related to their relative aromaticity compared to the carbon archetype. Transition metal-containing metallabenzenes are also implicated in certain catalytic processes such as alkyne metathesis polymerization; however, these transition metal-based metallaaromatic compounds have not been developed as a catalyst. Herein, we describe an effective strategy to generate diverse arrays of ruthenabenzenes and demonstrated them as an aromatic equivalent of the Grubbs-type ruthenium alkylidene catalysts. These ruthenabenzenes can be prepared via an enyne metathesis and metallotropic [1,3]-shift cascade process to form alkyne-chelated ruthenium alkylidene intermediates followed by spontaneous cycloaromatization. The aromatic nature of these complexes was confirmed by spectroscopic and X-ray crystallographic data, and the mechanistic pathways for the cycloaromatization process were studied by DFT calculations. These ruthenabenzenes display robust catalytic activity for metathesis and other transformations, which illustrates that metallabenzenes are not only compounds of structural and theoretical interests but also are a novel platform for new catalyst development.
Vinylogous Nicholas reactions in the synthesis of bi- and tricyclic cycloheptynedicobalt complexes
Kolodziej, Izabela,Green, James R.
, p. 10852 - 10864 (2015/11/17)
The Lewis acid mediated intramolecular Nicholas reactions of allylic acetate enyne-Co2(CO)6 complexes afford cycloheptenyne-Co2(CO)6 complexes in three manifestations. Electron rich aryl substituted alkyne complexes give tricyclic 6,7,x-benzocycloheptenyne complexes, with x = 5, 6, or 7. Allylsilane substituted complexes afford exo methylene bicyclic x,7-cycloheptenyne complexes (x = 6,7). The allyl acetate function may also be replaced by a benzylic acetate, to afford dibenzocycloheptyne-Co2(CO)6 complexes. Following reductive complexation, the methodology may be applied to the synthesis of the icetexane diterpene carbon framework.
Formation of condensed 1 H-pyrrol-2-ylphosphonates and 1,2-dihydropyridin- 2-ylphosphonates via Kabachnik-fields reaction of acetylenic aldehydes and subsequent 5-exo-dig or 6-endo-dig cyclizations
Buk?naitienè, Rita,Urbanaitè, Aurelija,?ikotienè, Inga
, p. 6532 - 6553 (2014/08/05)
Kabachnik-Fields reactions of various carbocyclic or heterocyclic acetylenic aldehydes together with subsequent Lewis acid catalyzed cyclizations have been studied. It was found that 5-exo-dig versus 6-endo-dig cyclization mode strongly depends on the structure of starting materials. Thus, nonaromatic acetylenic α-anilinomethylphosphonates underwent gold(III)-catalyzed or iodine-mediated 5-exo-dig cyclization to 1H-pyrrol-2-ylphosphonates. In contrast, electron-withdrawing heteroaromatic substrates formed 1,2-dihydropyridin-2-ylphosphonate ring containing materials via an exclusive 6-endo-dig ring-closure process. The dual mode of cyclization is possible only for α-amino (2-alkynylphenyl)methylphosphonates containing a benzene ring.
Copper catalyzed synthesis of highly substituted pyrrole and isoindole derivatives
Nandi, Sukla,Ray, Jayanta K.
, p. 6203 - 6206 (2011/11/29)
We have developed an efficient synthesis of highly substituted pyrrole and isoindole derivatives using copper(I) catalyst. This methodology is helpful for the synthesis of some quinones bearing annealed N-heterocyclic natural products.
Gold-catalyzed cascade friedel-crafts/furan-yne cyclization/heteroenyne metathesis for the highly efficient construction of phenanthrene derivatives
Chen, Yifeng,Li, Guijie,Liu, Yuanhong
supporting information; experimental part, p. 392 - 400 (2011/04/22)
A rapid access to highly substituted phenanthrenyl ketones through gold-catalyzed cyclization of 1,6-diyn-4-en-3-ols with furans has been developed. Gold catalysts are effective to catalyze three cascade processes involving Friedel-Crafts/furan-yne cyclization/heteroenyne metathesis through C-O bond and alkyne activation. This method offers several advantages such as high selectivities and easily accessible starting materials.
Copper-catalyzed addition of water affording highly substituted furan and unusual formation of naphthofuran ring from 3-(1-alkenyl)-2-alkene-1-al
Jana, Rathin,Paul, Sunanda,Biswas, Anup,Ray, Jayanta K.
supporting information; experimental part, p. 273 - 276 (2010/03/26)
We have developed a novel one-pot reaction to generate highly substituted furan through the addition of water followed by oxidation and unusual cyclization to naphthofuran ring under the same reaction condition.
Ring size and substituent effects in oxyanion-promoted cyclizations of enyne-allenes: Observation of a Myers-Saito cycloaromatization at cryogenic temperature
Waddell, Michelle K.,Bekele, Tefsit,Lipton, Mark A.
, p. 8372 - 8377 (2007/10/03)
A series of acetoxy-substituted enyne-allenes, fused to cyclopentene and cyclohexene ring systems, were synthesized and treated with methyllithium to generate the corresponding enolates. It was found that whereas the cyclohexannulated examples underwent e
Ring strain effects in enyne-allene thermolysis: Switch from the Myers-Saito reaction to the C2-C6 biradical cyclization
Schmittel, Michael,Steffen, Jens-Peter,Auer, Dominik,Maywald, Michael
, p. 6177 - 6180 (2007/10/03)
The mode of the thermal cyclization of enyne-allenes 1 depends on ring strain effects: when the ene functionality is part of a benzene, cyclohexene or cycloheptene ring the novel C2-C6 biradical cyclization is observed, while when it is part of a cyclopentene ring the Myers-Saito cycloaromatization is registered.
Benzocyclobutadienes via electrocyclizations of (Z,Z)-3,5-octadiene-1,7-diynes leading to dimers with unusual polycyclic structures
Wang, Kung K.,Liu, Bin,Petersen, Jeffrey L.
, p. 6860 - 6867 (2007/10/03)
(Z,Z)-3,5-Octadiene-1,7-diynes 15a-e were synthesized by condensation of enynyl aldehydes 12a-e with allenylborane 11 to furnish enynyl alcohols 14a-e followed by the elimination step of the Peterson olefination reaction. Desilylation of 15a with tetrabut
An efficient synthesis of enyne[3]cumulenes
Wang, Kung K.
, p. 3785 - 3788 (2007/10/02)
The Pd(PPh3)4-catalyzed cross coupling between 3 and terminal alkynes furnished enynyl aldehydes 4, which were converted to 6 by condensation with 5. Sequential treatment of 6 with n-butyllithium, methanesulfonyl chloride, and tetrab
