No abstract

A highly enantioselective aminalization of 2‐aminobenzenesulfonamides and aldehydes catalyzed by a novel cyclopentadiene‐based chiral carboxylic acid has been realized. The cost‐effective and readily synthesized cyclopentadiene‐based chiral carboxylic acid was found to be a highly reactive Brønsted acid for this transformation, affording benzothiadiazine class of cyclic aminals with up to 98 % ee.

A metal-free reduction of nitro aromatics mediated by di­boronic acid with water as both the hydrogen donor and solvent under mild conditions has been developed. A series of aromatic amines were obtained with good functional group tolerance and in good yields.

A novel full atom-economic process for the transformation of alkynes into chiral alcohols by TfOH-catalyzed hydration coupled with Ru-catalyzed tandem asymmetric hydrogenation in TFE under simple conditions has been developed. A range of chiral alcohols was obtained with broad functional group tolerance, good yields, and excellent stereoselectivities.

A facile and green approach was developed for the synthesis of 4(3H)-quinazolinones by using camphorsulfonic acid as a catalyst in an aqueous solution of biodegradable ethyl lactate. Various 2-aryl-, 2alkyl-, and 2-(4-oxoalkyl)quinazolinones were obtained by cyclization of 2-aminobenzamides with a wide range of acyclic or cyclic 1,3-diketones via C-C bond cleavage in satisfactory-to-excellent yields. Scheme 1. A green approach to 4(3H)-quinazolinones.