Ruthenium-Catalyzed Propargylation of Aromatic Compounds with Propargylic Alcohols

Abstract

A novel ruthenium-catalyzed propargylation of aromatic compounds with propargylic alcohols has been found to afford the corresponding propargylated aromatic products in good yields with complete regioselectivity. The catalytic reaction provides a potential usefulness for practical application in organic synthesis, because the selective propargylation of aromatic compounds with an aromatic C-H bond cleavage is generally difficult.

Activation of Mononuclear Arene Ruthenium Complexes for Catalytic Propargylation Directly with Propargyl Alcohols

“…[4,5,9] However, for Nishibayashis catalyst very similar diruthenium complexes have been reported to be active also for the propargylic substitution of internal alkynols. [7] On the other hand, catalysts with other metals (Re, [12] Au [13] ) and organic acids, [14] offer their best results with internal alkynols.…”

“…[4][5][6][7] A nucleophilic addition on the electrophilic g-carbon in allenylidene metal intermediates seems to be the key step. This innovative transformation represents a catalytic alternative to the Nicholas reaction, which requires a stoichiometric amount of cobalt complex to stabilize the propargyl cation intermediate.…”

“…NMR, IR and analysis data for 2-(1-phenyl-2-propynyl)furan (4a), 2-methyl-5-(1-phenyl-2-propynyl)furan (4b), 2-methyl-5-(1-phenyl-2-heptynyl)furan (4c), 2-(1,3-diphenylprop-2-ynyl)furan (4d) and 2-(1,3-diphenylprop-2-ynyl)-5-methylfuran (4e) match well with those previously reported. [5] See yields in Table 1. corresponding propargyl alcohol (132 mg of 1a, 188 mg of 1d, 208 mg of 1e) and 1 mL of 2-propyn-1-ol, 3-butyn-1-ol or 2-propen-1-ol were added. After heating overnight at 60 8C, the solvent was removed under vacuum and the residue extracted with 2 5 mL of Et 2 O. Purification of the product was carried out by column chromatography (silica, pentane), giving the corresponding propargyl ether as yellow oils.…”

Ruthenium‐katalysierte Reaktionen – eine Schatzkiste für atomökonomische Umwandlungen

“…(21)], [69] 1,3-Dicarbonylverbindungen [Gl. (22)] [70] sowie Amiden, Aminen, Phosphinoxiden, [67] Phenolen [71] und Olefinen.…”

Alcohols in direct carbon-carbon and carbon-heteroatom bond-forming reactions: recent advances

“…The review covers both C-C and C-heteroatom bond formation. 92 Furthermore, alkylation of furans by benzyl, allyl, and propargyl alcohols 80,[93][94][95][96] in the presence of Lewis acids as a catalyst has been also reviewed 17 and of the many results a selection is shown in Table 11. The catalytic nucleophilic substitution of tertiary alcohols of type 15, using carbon or heteroatom based nucleophiles in the presence of Lewis acid has been the several publications 79,85,98,99 as well as a review 20 and selected results are shown in Table 12.…”