An efficient N,N′‐dioxide–lanthanum(III) complex catalytic system has been developed for the diastereo‐ and enantioselective Michael‐initiated ring‐closure (MIRC) reaction of 2‐cyano‐3‐arylacrylates with 2‐bromomalonates. Various chiral cyclopropanes with multiple substitutions were obtained in high yields (up to 93%) with excellent dr (>95:5 dr) and good ee values (up to 91% ee). The catalytic system
providing a facile entry to highly complex molecular frameworks with excellent stereocontrol. For the Diels-Alder reactions with 3-olefinic oxindoles, spirocyclic oxidoles are formed in high yields, and with enantioselectivities in the range of 94-98% ee. It is demonstrated, that some of these products can be transformed into the hexahydrofuro[2,3-b]indole fragment. The organocatalytic trienamine concept
Palladium-Catalyzed Hydrocyanation of Ynoates: En Route to the Stereodivergent Synthesis of β-Cyanated α,β-Unsaturated Esters via Ligand Controlled Regio- and Stereoselectivity
A Pd-catalyzed highly regio- and stereoselective hydrocyanation was developed, providing a novel approach to the stereodivergent synthesis of β-cyano-substituted acrylates in good yields with a wide substrate scope. The judicious selection of ligands was crucial for elegant control over the stereodivergence. Furthermore, the success of the E-hydrocyanation hinges on the right matching of Pd and L1
with cyanoaokenes substituted with ester groups catalyzed by a Sn and Mg ate complex. The diastereoselectivity was affected by the halogen of the catalyst and electron‐withdrawing groups on the cyanoalkene. The transformation of the spirohexane was carried out to afford a cyclopentanoid which has been prepared only by a transition metal catalyst.
(CsNF)-catalyzed Knoevenagel reaction in green solvent, namely aqueousmethanol, was investigated. CsNFs solely catalyzed the desired C–C bond formations in high yield with high selectivity, while conventional small-molecule amines, such as n-hexylamine and triethylamine, inevitably promoted transesterification to produce a large amount of solvolysis byproducts. Structural and chemical analyses of CsNFs suggested