Auto tandem triple cascade organocatalysis: access to bis-lactone and butenolide derivatives.

The synthesis of bis-lactone and butenolide derivatives was described using alkylidene Meldrum's acid as nucleophiles. The process operates in a triple cascade through an auto tandem catalysis promoted by DBU.

2-Hydroxymethyl-18-crown-6 as an efficient organocatalyst for α-aminophosphonates synthesized under eco-friendly conditions, DFT, molecular docking and ADME/T studies.

Eco-friendly and simple procedure has been developed for the synthesis of α-aminophosphonates that act as topoisomerase II α-inhibiting anticancer agent, using 2-hydroxymethyl-18-crown-6 as an unexpected homogeneous organocatalyst in multicomponents reaction of aromatic aldehyde, aniline and diethylphosphite in one pot via Kabachnik-Fields reaction. This efficient method proceeds with catalytic amount, transition metal-free, at room temperature within short reaction time, giving the α-aminophosphonates derivatives (4a-r) in high chemical yields (up to 80%). Theoretical DFT calculations of three compounds (4p, 4q and 4r) were carried out in a gas phase at CAM-B3LYP 6-31G (d,p) basis set to predict the molecular geometries and chemical reactivity descriptors. The frontier orbital energies (HOMO/LUMO) were described the charge transfer and used to predict structure-activity relationship study. Molecular electrostatic potential (MEP) has also been analyzed. Molecular docking studies are implemented to analyze the binding energy and compared with Adriamycin against 1ZXM receptor which to be considered as antitumor candidates. In silico pharmacological ADMET properties as Drug likeness and oral activity have been carried out based on Lipinski's rule of five.Communicated by Ramaswamy H. Sarma.

Access to valuable building blocks by the regio- and enantioselective ring opening of itaconic anhydride by lipase catalysis.

Herein, we report for the first time the highly regio- and enantioselective ring opening of a biobased itaconic anhydride catalyzed by the Pseudomonas cepacia lipase (PCL) in tert-butyl methyl ether (TBME) at room temperature. This method is easy, efficient and eco-friendly and can be performed in one step with a series of highly valuable monoester itaconates (achiral or enantioenriched) using various alcohols as nucleophiles with 100% atom economy. In all cases, the ß-monoester isomer was the predominant product of the reaction. Using achiral primary alcohols as substrates, a variety of novel itaconates were obtained in moderate to excellent yields (50-90%). For select examples, product characterization was carried out using X-ray diffraction, in addition to the standard techniques. The application of this approach was performed for the preparation of enantioenriched 4-monoester itaconates via enzymatic kinetic resolution.

Enantioselective hydrophosphonylation of N-Boc imines using chiral guanidine-thiourea catalysts.

The enantioselective hydrophosphonylation of N-Boc imines was investigated using a new family of pseudo-symmetric guanidine-thiourea catalysts, providing α-amino phosphonates in moderate to high yields with good enantioselectivity. The catalyst was heterogenized by polymerization with styrene and the resulting catalyst was applied to reactions under continuous-flow conditions.

Fiaud's Acid, a novel organocatalyst for diastereoselective bis α-aminophosphonates synthesis with in-vitro biological evaluation of antifungal, antioxidant and enzymes inhibition potential.

(S, S)-1-hydroxy-1-oxo-2-c,5-t-diphenylphospholane or Fiaud's acid is used as a novel and effective chiral organocatalyst for bis α-aminophosphonates synthesis with excellent diastereoselectivity and yields within short reaction time. All synthesized bis α-aminophosphonates revealed a good to excellent antifungal capacity, where the six compounds 4a, 4b, 4e, 4h, 4k and 4l are the best fungicide inhibiting the growth of Fusarium oxysporumandBotrytis cinereaby 65% to 84% with IC50 values <0.02 mg/mL. Similarly, these six products exhibited a strong antioxidant effect, whereas a low inhibition activity was obtained with both AChE and BChE. Furthermore, they displayed a very weak inhibitory activity against tyrosinase except for the compound4l.These findings suggest a possible use of these compounds as synthetic pesticides with less hazardous effects with antioxidant, and anti-tyrosinase properties.

Alkylidene Meldrum's Acids as Platforms for the Vinylogous Synthesis of Dihydropyranones.

Upon Brønsted base organocatalysis, ketone-derived alkylidene Meldrum's acids proved to be competent vinylogous platforms able to undergo a formal (4+2) cycloaddition reaction with dihydro-2,3-furandione, providing an unprecedented route to 3,6-dihydropyran-2-ones as spiro[4.5]decane derivatives with up to 98 % ee thanks to the commercially available Takemoto catalyst. Preliminary investigation showed that this reaction could be extended to other activated ketones, establishing these alkylidene Meldrum's acids as a novel C4-synthon in the vinylogous series.

S-Trifluoromethyl Sulfoximine as a Directing Group in Ortho-Lithiation Reaction toward Structural Complexity.

The first use of the NH S-trifluoromethyl sulfoximine as an ortho directing group is described for the functionalization of the aryl group bonded to the sulfur atom. Various electrophiles (halogen, carbon, oxygen, sulfur, boron, etc.) are introduced on the aromatic ring. Cyclic S-trifluoromethyl sulfoximines are synthesized either with properly chosen electrophiles or by structural adjustment of o-azido sulfoximines. Fluorinated analogues of prazosin are also prepared.

First isolation of enantiopure perfluoroalkylated sulfilimines and sulfoximines.

Mono-, di- and trifluoromethyl sulfilimines and sulfoximines have been isolated for the first time in enantiopure form by separation of the racemate by supercritical fluid chromatography. The electrophilic trifluoromethylating Shibata reagent has been prepared as a single enantiomer.