Asymmetric hydrogenation plays an important role in organic synthesis, but that of the challenging substrates such as N-unprotected imines, enamines, and N-heteroaromatic compounds (1H-indoles, 1H-pyrroles, pyridines, quinolines, and quinoxalines) has only received increased attention in the past three years. Considering the interaction modes of a Brønsted acid with a Lewis base, Brønsted acids may be used as the ideal activators of C=N bonds. This Minireview summarizes the recent advances in transition-metal-catalyzed, Brønsted acid activated asymmetric hydrogenation of these challenging substrates, thus offering a promising substrate activation strategy for transformations involving C=N bonds.

The enantioselective construction of axially chiral compounds by electrophilic carbothiolation of alkynes is disclosed for the first time. This enantioselective transformation is enabled by the use of a Ts‐protected bifunctional sulfide catalyst and Ms‐protected ortho‐alkynylaryl amines (Ts=tosyl; Ms=mesyl). Both electrophilic arylthiolating and electrophilic trifluoromethylthiolating reagents are suitable for this reaction. The obtained products of axially chiral vinyl–aryl amino sulfides can be easily converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl–aryl amines, and other valuable difunctionalized compounds.

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Construction of the benzene ring was efficiently realized through a palladium(ii)-catalyzed, copper(ii)-mediated domino dehydrochlorination/alkenylation/cycloaddition–oxidation sequence.

Copper-catalyzed borylation of β-trifluoromethyl-α,β-unsaturated ketones was efficiently achieved by means of bis(pinacolato)diboron (Bpin), affording the enantioenriched products in good yields with high enantioselectivities. CuI and (R,S)-Josiphos consist of the most efficient catalyst system under mild conditions. In the absence of the chiral ligand, the reactions could be performed more efficiently to form β-ketone derivatives which were directly borylated and indirectly trifluoromethylated at the β-carbon atom of the α,β-unsaturated ketone substrates. The present protocol provides a promising method to access a stereogenic carbon center bearing both CF and organoboron functional groups.

Highly efficient arylations of β‐chloro ketones and their ester and amide derivatives were achieved by means of domino dehydrochlorination/Rh(I)‐catalyzed conjugate addition. In situ generated vinyl ketones and their analogues were identified as the reaction intermediates. The present synthetic protocol provides a concise route to (chiral) β‐aryl ketones, esters, and amides.

Chiral selenide-catalyzed enantioselective trifluoromethylthiolation of 1,1-disubstituted alkenes is disclosed. Various chiral trifluoromethylthiolated 2,5-disubstituted oxazolines were obtained in good yields with high enantioselectivities.

Rhodium(iii)-catalyzed conjugate addition of aromatic and olefinic C-H bonds to CF3-substituted unsaturated ketones was efficiently achieved. Both arene and olefin substrates bearing a chelate assisted-directing group were coupled with a variety of β-trifluoromethyl-α,β-unsaturated ketones with excellent atom-economy, high yields, and broad substrate scopes.