This account summarizes our recent work on the pK a scales of some frequently used organocatalysts, especially those of hydrogen-bond-donor catalysts and stronger Brønsted acid catalysts. Most of these pK a values were obtained by the Bordwell overlapping indicator method, which is known to provide high accuracy. Linear free-energy relationships associated with pK a values are discussed in relation to understanding of reaction mechanisms.1 Introduction2 Single Hydrogen-Bonding Donors2.1 Proline-Type Organocatalysts2.2 Cinchona Alkaloids Bearing a Hydrogen-Bonding Donor in the 6′-Position3 Double-Hydrogen-Bonding Donors3.1 Thioureas3.2 Squaramides3.3 BINOLs4 Stronger Brønsted Acids5 N-Heterocyclic Carbenes6 Summary and Outlook

Herein we report the catalytic asymmetric synthesis of a unique family of axially chiral enamides in good yields with excellent enantioselectivities under mild conditions. These new axially chiral compounds feature...

Difluorinated carbonyl has been identified as the basic skeleton of multitudinous bio-logically active molecules. However, strategies for asymmetrically introducing such important moiety remains a formidable challenge. Herein, we reported a...

Treatment of propargylamides or propargylamidines with cesium carbonate in DMSO results in the formation of the corresponding oxazoles or imidazoles in good yields. A large variety of substrates with various functional groups are tolerated. DFT study on a model substrate reveals that the reactions proceed via a sequence involving allene formation, intramolecular cyclization, and double‐bond isomerization.