Highly Regioselective Au(I)-Catalyzed Hydroamination of Ynamides and Propiolic Acid Derivatives with Anilines

Palladium-catalyzed hydroacyloxylation of ynamides

In the presence of substoichiometric Pd(OAc)(2), carboxylic acids undergo highly regio- and stereoselective additions to ynamides to provide α-acyloxyenamides.

Metal-free halonium mediated acetate shifts of ynamides to access α-halo acrylamides/acrylimides

A metal-free acetate shift of 3-acetoxy ynamides to access α-iodo, bromo, and chloro acrylamides/acrylimides under very mild conditions is demonstrated. The inherent alkyne activation of ynamides is sufficient to ensure the α-halo acrylamides/acrylimides in high yields without the addition of a catalyst. In all cases high Z-stereoselectivity is observed.

Palladium-catalyzed intramolecular trapping of the Blaise reaction intermediate for tandem one-pot synthesis of indole derivatives

Palladium-catalyzed intramolecular N-arylative and N-alkylative/N-arylative trappings of the Blaise reaction intermediates could be a new route to construct the indole moiety in a tandem one-pot manner from nitriles.

Site-specific introduction of gold-carbenoids by intermolecular oxidation of ynamides or ynol ethers

Ynamides and ynol ethers undergo intermolecular gold-catalysed reaction with a nucleophilic oxidant to access metal-carbenoid reactivity patterns. A site-specific oxidation/1,2-insertion cascade is used for a general access to functionalised α,β-unsaturated carboxylic acid derivatives and vinylogous carbimates.

Access to 2,5-diamidopyrroles and 2,5-diamidofurans by au(i)-catalyzed double hydroamination or hydration of 1,3-diynes

A Au(I)-catalyzed hydroamination or hydration of 1,3-diynes to access 2,5-diamidopyrroles and 2,5-diamidofurans has been developed. This method can also be expanded to 2,5-disubstituted furans and 1,2,5-trisubstituted pyrroles including the formation of deuterated heterocycles and (18)O-labeled furans.

Pd-catalyzed C-N bond formation with heteroaromatic tosylates

A protocol for the palladium(0)-catalyzed amidation of heteroaromatic tosylates was successfully developed. The methodology proved to be effective for a variety of heteroaryl tosylates including the pyridine, pyrimidine, quinoline and quinoxaline ring systems. Successful carbon-nitrogen bond formation with these heteroaryl tosylates could be performed with a wide range of primary amides, oxazolidinones, lactams, anilines and indoles, including one cyclic urea. Moreover, this C-N bond forming reaction provided products with high structural diversity. The coupling reaction was also amenable to scale up applications.

A divergent mechanistic course of Pd(0)-catalyzed aza-Claisen rearrangement and aza-Rautenstrauch-type cyclization of N-allyl ynamides

A fascinating mechanistic study of ynamido-palladium-pi-allyl complexes is described that features isolation of a unique silyl ketenimine via aza-Claisen rearrangement, which can be accompanied by an unusual thermal N-to-C 1,3-Ts shift in the formation of tertiary nitriles and a novel cyclopentenimine formation via a palladium-catalyzed aza-Rautenstrauch-type cyclization pathway.

A Stereoselective Intramolecular Cyclopropanation via a De Novo Class of Push-Pull Carbenes Derived from DMDO-Epoxidations of Chiral Ynamides

This work describes the first examples of diastereoselective intramolecular cyclopropanations of a de novo class of push-pull carbenes derived from DMDO-epoxidations of chiral ynamides. This reaction sequence essentially constitutes a tandem epoxidation-cyclopropanation that effectively gives arise to a series of structurally unique amido-cyclopropanes. A plausible mechanistic model is proposed revealing insights into this novel cyclopropanation process.

Synthesis of ketene N,N-acetals by copper-catalyzed double-amidation of 1,1-dibromo-1-alkenes

An efficient procedure for the preparation of ketene N,N-acetals by copper-catalyzed double amidation of 1,1-dibromo-1-alkenes is reported. The reaction was found to be general, and ketene aminals could be obtained in good yields when potassium phosphate in toluene was used at 80 degrees C. The reaction was found to proceed through a regioselective monocoupling reaction followed by dehydrobromination and hydroamidation.