We herein report a computational study of the bonding in gold(I) vinylidene complexes and compare them to their carbene and CO analogues. The relevance of these intermediates is analysed for the intramolecular cyclisation leading to vinyl sulfonates.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.201504511 | DOI Listing |
Chem Commun (Camb)
August 2022
Departmento de Química Orgánica e Inorgánica Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, Julian Clavería 8 33006, Oviedo, Spain.
The high reactivity of gold-vinylidene complexes, generated by [1,2]-bromine shift from the corresponding 1-bromoalkynes, allows the activation of one of the strongest bonds in organic chemistry (Si-O), strategically placed at the -position. In this way, the synthesis of 3-bromo-2-silylbenzofuranes is achieved in good yields. Several substituents with different electronic properties and substitution patterns are well tolerated on the tethering aromatic ring as well as a number of silyl groups on the O-atom.
View Article and Find Full Text PDFDalton Trans
December 2020
Institute of Chemistry and Chemical Technology SB RAS, Krasnoyarsk Research Center, Siberian Branch of the Russian Academy of Sciences, Akademgorodok 50-24, Krasnoyarsk, 660036, Russian Federation.
A series of reactions of Cp(CO)2Mn[double bond, length as m-dash]C[double bond, length as m-dash]CHPh with different gold(i) complexes of [Au-C[triple bond, length as m-dash]C-R]n (R = 4-C5H4N, C6H5) and (tht)AuCl yielded one novel trinuclear MnAuMn cluster. The structure of this cluster can be rationalized as being formed of a vinylidene Mn-Au binuclear and Mn-acetylide fragments, and the binding between those is achieved mainly through the sharing of the electron pair of the single Mn-C σ-bond of an acetylide unit with the gold center.
View Article and Find Full Text PDFChemistry
February 2021
Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
A simple gold-catalyzed annulation of 1,8-dialkynylnaphthalenes utilizing a cationic gold catalyst was developed. Such a peri-position of two alkynyl substituents has not been studied in gold catalysis before. Dependent on the substrate, the reactions either follow a mechanism involving vinyl cation intermediates or involve a dual gold catalysis mechanism which in an initial 6-endo-dig-cyclization generates gold(I) vinylidene intermediates that are able to insert into C-H bonds.
View Article and Find Full Text PDFOrg Lett
August 2019
Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo , C/Julián Clavería 8 , 33006 Oviedo , Spain.
(Acetonitrile)[1,3-bis(2,6-diisopropylphenyl)-imidazole-2-ylidene] gold(I) catalyzes the cycloisomerization of 2-(iodoethynyl)aryl esters to give 3-iodo-2-acyl benzofurans. This catalytic transformation is the result of an unprecedented selective synthetic event, which comprises a [1,2]-iodine shift, a C-O ring-closure step, and a C-C bond-formation that installs the ketone functionality into the new ring. Experimental evidence supports the involvement of a β-iodo-substituted gold vinylidene as the intermediate species.
View Article and Find Full Text PDFChem Commun (Camb)
April 2019
Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
Gold(ii) species catalyse the cyclisation of N(2-propyn-1-yl)benzamide to 2-phenyl-5-vinylidene-2-oxazoline without halide abstraction while the saturated gold(i) complex is inactive. Redox-switching between gold(ii) and gold(i) turns catalytic turnover on and off.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!