A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide broad variety interesting heterocycles. Key success this transformation remarkable catalytic cleavage present carbon–carbon triple bond using specific catalyst 2-di...

The Meyer-Schuster rearrangement is an efficient method to prepare ?,?-unsatured carbonyl compounds starting from propargylic alcohols and this review presents the remarkable progress made during last decade in reaction. New catalytic systems have been discovered many elegant applications reported for rearrangement. To be noticed particular are new cascade processes affording a wide range of ca...

The regioselective conversion of propargylic alcohols into previously unreported α,α-diiodo-β-hydroxyketones was achieved by treatment with N-iodosuccinimide in the presence of a gold catalyst. The corresponding α,α-dichloro-β-hydroxyketones were obtained by treatment with trichloroisocyanuric acid in the absence of a catalyst. The latter reaction can be extended to other alkynols. These transf...

Homoallenic alcohols are prepared from propargyl vinyl ethers using a trinuclear gold(I)-oxo complex, [(Ph3PAu)3O]BF4, as a catalyst for propargyl Claisen rearrangement at room temperature. The gold(I)-catalyzed reaction is effective for a diverse collection of propargyl vinyl ethers, including substrates containing aryl and alkyl groups at the propargylic position, and hydrogen, aryl, and alky...

Nucleophilic addition to alkynes represents an attractive approach to the synthesis of olefins. Obstacles to this strategy include the low reactivity of alkynes toward many organometallic reagents and difficulties associated with controlling the regioselectivity of addition. Here we demonstrate that Fe(III) salts are effective precatalysts for the carbometalation of alkynes. Primary and seconda...

Gold-catalyzed intermolecular oxidation of carboxylates of primary or secondary propargylic alcohols are realized with excellent regioselectivity, which is ascribed to inductive polarization of the C-C triple bond by the electron-withdrawing carboxy group. The gold carbene intermediates thus generated undergo selective 1,2-acyloxy migration over a 1,2-C-H insertion, and the selectivities could ...

The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C–O, C–N and C–C bonds in technical acetone, and in air. Good to excellent yields were obtained using low acid loading (typically 1 mol %) under simple reaction conditions and good chemoselectivity.

Brønsted acid promoted nucleophilation of propargylic alcohols during the Meyer-Schuster rearrangement (M-S) has been introduced. A novel concept of reverse polarization of the M-S intermediate allenyl cation has been realized by employing a cis-enoate assisted strategy. This idea is well demonstrated by the metal free synthesis of complex, highly functionalized cyclic as well as acyclic α-aryl...