Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

Abstract

SummaryA new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.

Synthesis, Crystal Structure, and DFT Calculations of 1,3-Diisobutyl Thiourea

“…Such ligands are capable of affording complexes with metal ions; the resultant complexes have been reported to have imperative antimicrobial [4] and anticonvulsant [5] applications. Thiourea derivatives and their complexes have numerous catalytic applications in asymmetric organocatalysis [6][7][8], have been used as cocatalysts in Pauson-Khand reactions [1], Pd-catalyzed reactions [1,9], Heck and Suzuki coupling reactions, and so forth [2,9]. Thiourea derivatives got much more attention in the field of highly enantio-and diastereoselective catalysis [10] and have also been applied as cocatalysts in nanoparticles and a number of other types of reactions [11,12].…”

Design and synthesis of novel indoline-(thio)urea hybrids

“…4). [24] The treatments with Michael acceptors such as 2-cyclohexen-1-one, trans-chalcone, methyl trans-cinnamate and crotonaldehyde with indole and indoline in the presence of catalysts (20 mol%) in toluene did not result in any detectable reactions. Newly designed catalysts gave racemic products although with at least the same level of reactivity as catalysts reported in the literature.…”

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

“…This may lead to activated forms of the substrates allowing the corresponding reaction to occur [9–11]. For example, Jacobsen and co-workers pioneered an effective chiral thiourea catalyst which was employed in an asymmetric Strecker reaction [12–13].…”