The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.

Cascade reactions involving a catalytic carbene/alkyne metathesis (CAM) process through a vinyl carbene intermediate provide an efficient and step-economic approach for the construction of polycyclic frameworks with structural diversity.

A formal [5 + 3] cycloaddition of zwitterionic allylpalladium intermediates with 1,3-dipoles is developed, providing N,O-containing eight-membered heterocyclic compounds in high yields. Catalytically generated zwitterionic allylpalladium intermediates in situ from vinylethylene carbonates or vinyloxiranes acted as dipolarophile.

An unprecedented gold-catalyzed bicyclization reaction of diaryl alkynes has been developed for the synthesis of indoles in good to high yields. Mechanistically, this alkyne bifunctionalization transformation was terminated by a stepwise formal X-H insertion reaction to furnish the corresponding polycyclic-frameworks with structural diversity, and the key intermediate 3 H-indole was isolated and characterized for the first time. In addition, further transformation of these generated tetracyclic-indoles with PCC as the oxidant provided straightforward access to the spirooxindoles in high yields.

A gold-catalyzed carbocyclization of alkynes with a pendant diazo group that is completed by reaction with a protic nucleophile for the synthesis of indenol derivatives with a tertiary center is described. Mechanistic studies and DFT calculations indicate that the transformation is initiated by a gold-promoted 5-endo-dig carbocyclization to form the key intermediate vinyl gold carbene, which is intercepted by an unprecedented vinylogous addition and followed by external protic nucleophile-assisted protodeauration. Furthermore, in this catalytic alkyne transformation, various nucleophiles, including water, commercially available 1°, 2°, and 3° alcohols, menthol, d-galactose, cholesterol, steroid, etc., all perform well under these mild conditions to produce the corresponding indenol derivatives in high yields with structural diversity.