thiourea and rosin

We present herein for the first time the synthesis and preliminary biological evaluation of various modified chromanes via a rosin-derived tertiary amine-thiourea-catalyzed highly enantioselective Friedel-Crafts alkylation reaction.

Topics: Alkylation; Amines; Antineoplastic Agents; Catalysis; Chromans; Resins, Plant; Stereoisomerism; Thiourea

A highly efficient diastereo- and enantioselective Mannich reaction of lactones with a variety of N-Boc-aldimines by using bifunctional rosin-derived amine thiourea catalysts was investigated for the first time, in general, affording the adducts bearing quaternary stereogenic centers with high levels of enantio- and diastereoselectivity (up to 99% ee, and >20:1 dr).

Topics: Amines; Catalysis; Lactones; Mannich Bases; Resins, Plant; Stereoisomerism; Thiourea

Starting from commercially available natural rosin derivatives, a class of bifunctional rosin-derived amine thiourea catalysts were designed and synthesized. The doubly stereocontrolled asymmetric addition of a variety of 1,3-dicarbonyl compounds to nitroalkenes was investigated. These rosin-derived chiral thioureas have been shown to serve as effective catalysts for this double-sterecontrolled organocatalytic process by the investigation of the efficacy of the thiourea catalysts in comparison with other thiourea catalysts reported. In addition, these chiral thiourea ligands are easily available. Furthermore, the rosin-derived tertiary amine-thiourea was also revealed to be highly efficient for construction of contiguous stereogenetic centers containing an asymmetric quaternary carbon by the Michael reaction of alpha-substituted beta-ketoesters to nitroalkenes.

Topics: Alkenes; Amines; Catalysis; Esters; Molecular Structure; Nitro Compounds; Resins, Plant; Stereoisomerism; Thiourea