Sodium Bicarbonate Catalyzed Stereoselective Isomerizations of Electron-Deficient Propargylic Alcohols to (Z)-Enones.

Iron-catalyzed carbometalation of propargylic and homopropargylic alcohols.

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...

Directed hydrozirconation of propargylic alcohols.

Hydrozirconation of alkynes with Cp2ZrH(Cl) (Schwartz reagent) generates vinyl zirconium species reliably, stereospecifically, and regioselectively. These organometallic reagents can participate in cross-coupling reactions, conjugate and nucleophilic additions, and can undergo carbonylation and halogenation.1 Hydrozirconation of terminal alkynes often proceeds with >50:1 selectivity to form the...

Cp2TiCl2-catalyzed cis-hydroalumination of propargylic amines with Red-Al: stereoselective synthesis of Z-configured allylic amines.

A titanium-catalyzed cis-hydroalumination of propargylic amines with Red-Al is described, which provides an efficient way to produce Z-configured allylic amines in good to excellent yields with high stereoselectivity and good regioselectivity. The hydride-bridged Al/Ti bimetallic species may act as a real catalyst in this reaction.

Copper-catalyzed tandem annulation/arylation for the synthesis of diindolylmethanes from propargylic alcohols.

Various highly substituted 2,3'-diindolylmethane heterocycles were prepared from propargylic alcohols and indole nucleophiles via a transition metal-catalyzed tandem indole annulation/arylation reaction for the first time. Among the metal catalysts we examined, the most economical copper(I) catalyst provided the highest efficiency. The indole nucleophiles could also be replaced by other electro...

Ruthenium-catalyzed enantioselective propargylation of aromatic compounds with propargylic alcohols via allenylidene intermediates.