A highly enantioselective dearomative Rautenstrauch rearrangement catalyzed by cationic (S)-DTBM-Segphosgold(I) is reported. This reaction provides a straightforward method to prepare enantioenriched cyclopenta[b]indoles. These studies show vast difference in enantioselectivity in the reactions of propargyl acetates and propargyl acetals in the chiral ligand-controlled Rautenstrauch reaction.

A trinuclear gold(I)-oxo complex, [(Ph3PAu)3O]BF4, serves as the catalyst for the stereocontrolled synthesis of 2-hydroxy-3,6-dihydropyrans from propargyl vinyl ethers. Importantly, the rearrangement proceeds with excellent diastereoselectivity, and the rearrangement of chiral nonracemic propargyl vinyl ethers proceeds with excellent chirality transfer to furnish enantioenriched pyrans. Additio...

3-Substituted 2,5-dimethylpyrazines were synthesized in high yields via a one-pot cascade annulation of easily available propargyl amine with aldehydes catalyzed by Au(PPh2Cy)Cl.

Both simple Ag(I) and Au(I) are effective catalysts for a tandem [3,3]-sigmatropic rearrangement/formal Myers-Saito cyclization of propargyl esters to form aromatic ketones. A mechanism in which the metal catalyzes both of these processes through alkyne activation is proposed. By using this method a wide range of aromatic structures including naphthyl, anthracenyl and indole ketones are availab...

The rearrangement of 1-ethynyl-2-propenyl pivaloates to cyclopentenones catalyzed by cationic triphenylphosphinegold(I) complexes is described. The reaction tolerates both alkyl and aryl substitution at the acetylenic and olefinic positions. Importantly, the gold(I)-catalyzed rearrangement of enantioenriched propargyl pivaloates proceeds with excellent chirality transfer, thus providing a pract...

The mechanism of aryl propargyl ether Claisen rearrangement in gas and solvent phase was investigated using DFT methods. Solvent phase calculations are carried out using N,N-diethylaniline as a solvent in the PCM model. The most favorable pathways involve a [3,3]-sigmatropic reaction followed by proton transfer in the first two steps and then deprotonation or [1,5]-sigmatropic reaction. Finally...

The present work describes, the reaction between disodium salt of 1,3-dihydroxybenzene (in situ formation) and propargyl bromide was carried out in a solid-liquid biphasic phase transfer catalytic system at 50°C. Higher selectivity of the bis-derivative (1,3-bis(prop-2-ynyloxy)benzene) was obtained under solid-liquid PTC condion. The conversion of propargyl bromide of more than 99% was achieved...

BACKGROUND The nature of the heteroatom substitution in the nitrogen of a 3-aza-Cope system is explored. RESULTS While N-propargyl isoxazolin-5-ones suffer 3-aza-Cope rearrangements at 60°C, the corresponding N-propargyl pyrazol-5-ones need a higher temperature of 180°C for the equivalent reaction. When the propargyl group is substituted by an allyl group, the temperature of the rearrangement...

Rotaxane-structure-specific Pd-catalyzed rearrangement of propargyl or allyl urethane groups to oxazolidinone moieties proceeded efficiently. The conversion took place successively by the translation of the wheel along the axle, thus providing a novel macrocyclic catalytic system.