The gold-catalyzed [3+3]-cycloaddition reaction of propargyl esters and azomethine imines has been developed. The reaction provides a rapid entry into a wide range of substituted tetrahydropyridazine derivatives from simple starting materials. A stepwise mechanism involving addition of the 1,3-dipole to a gold-carbenoid intermediate is proposed.

A combination of IPrAuNTf(2) as catalyst in the presence of Selectfluor has been successfully used for the high yielding synthesis of α-fluoroenones via 1,3-acyloxy rearrangement of propargyl acetates followed by Csp(2)-F bond formation, likely involving a redox Au(I)/Au(III) catalytic cycle.

A new copper-catalyzed reaction for the stereo- and regioselective synthesis of alkenyl diboronates and allenyl boronates is presented. In this process propargyl derivatives of strained three/four-membered rings were employed as substrates and B2pin2 was used as the boronate source. Selective formation of the alkenyl diboronate versus the allenyl boronate products was controlled by the choice o...

A novel and efficient Pd-catalyzed intermolecular [3 + 2] carbocyclization of alkynols and electron-deficient alkynes for the synthesis of halo-cyclopentadienes (Cps) has been developed. The present protocol employs simple propargyl alcohols as the C3 group to participate in the cyclization reaction, providing a highly convenient and atom-economical entry to the halo-cyclopentadiene framework.

Practical Fischer glycosidation was effected at room temperature or 60 degrees C by using 5 to 10 equiv. of TMSCl. The anomeric propargyl group formed by this method was found to be a versatile new protecting group, being stable in neat TFA but readily cleaved by treatment with Co2(CO)8 and TFA in CH2Cl2 via the formation of an alkyne-Co complex.

A novel method for synthesizing polymer nanopods from a linear polymer bearing pendant propargyl ether groups, using gold nanoparticles as both the template and the catalyst for the cross-linking reaction, is reported. The transformations involved in the cross-linking process are unprecedented on the surface of a gold particle. A tentative cross-linking mechanism is proposed.

A novel and practical two-step approach to an intriguing class of imidazo[1,5-a]pyrazines with exocyclic C=X (X = CH2, O) bonds is described. The process utilizes a sequential three-component reaction of propargyl amine or aminoester, 1,2-diaza-1,3-dienes and isothiocyanates to furnish functionalized 2-thiohydantoins which are transformed into thiohydantoin-fused tetrahydropyrazines by subseque...