Abstract We report a sustainable, transition-metal-free multicomponent reaction for the step-economical assembly of (E)-2-(benzo[1,2]dithiol-3-ylidene)acetonitriles. This straightforward protocol utilizes elemental sulfur as a practical sulfur source, alongside active acetonitriles and o-nitro/halobenzaldehydes. Operating under mild conditions, the methodology provides a highly efficient route to novel disulfa heterocycles, expanding the toolkit for synthetic and medicinal chemistry.

A highly efficient asymmetric (3+2) annulation between enals and isoindigos was achieved via the N-heterocyclic carbene-catalyzed addition of homoenolates to activated tetrasubstituted C=C double bonds. The protocol provided straightforward access to enantiomerically enriched dispirocyclopentanone bisoxindoles (up to 97% ee) with three contiguous stereocenters, two of which are highly congested vicinal all-carbon quaternary centers.

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.

A designed chiral thiourea‐iminophosphorane catalyst was developed to afford α‐acyloxythioesters through enantioselective acyl‐transfer/protonation of α‐acyloxy‐β‐ketosulfides. The desired reaction proceeded in good yields with high enantioselectivities using a chiral thiourea‐iminophosphorane bearing a pyrrolidine scaffold.

A catalytic enantioselective vinylogous domino reaction has been achieved from ketone-derived benzylidene Meldrum's acid and alpha-ketolactones to provide spirolactone dihydropyranones with more than 99% ee. An Auto Tandem Catalysis (ATC) process resulting from dual and complementary role of (DHQ)(2)PHAL organocatalyst resulted in a sequence involving an asymmetric vinylogous formal (4+2) cycloaddition of benzylidene and the subsequent kinetic resolution operating through a 1,3-prototropic shift leading to good yields (>50%) and the high selectivity.

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.

An efficient and flexible synthesis of a new class of chiral bifunctional NHC catalyst has been reported. These new imidazolylidene NHCs, bearing a (thio)urea function as a hydrogen bond donor promoted efficiently highly diastereoselective trans-cyclopentannulation of enals and enones in moderate to good yields (up to 69 % yield) along with excellent enantioselectivity (up to 96 % ee). This methodology could be applied to a large variety of substrates (30 examples).

Angewandte Chemie International EditionVolume 60, Issue 20 p. 11001-11021 Graphical AbstractFree Access Graphical Abstract: Angew. Chem. Int. Ed. 20/2021 First published: 03 May 2021 https://doi.org/10.1002/anie.202182011AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Volume60, Issue20May 10, 2021Pages 11001-11021 RelatedInformation

The development of new and more efficient catalytic systems is the subject of increasing attention from both academic and industrial research. Moreover, biomass is an endless supply of hydrocarbon materials that can be used as renewable raw materials for the development of new organic compounds. In this context, many research groups have devoted their works to products with a natural chirality source, non-toxic, biodegradable and usually cost effective for the development of new chiral catalysts. Some new chiral molecules derived from biomass such as carbohydrates and natural amino acids have been synthesized and used as chiral ligands or organocatalysts for asymmetric transformations leading to the formation of expected products in good yields with high enantioselectivities

A novel class of reversible chiral ammonium-based ionic liquids has been designed and synthesized. These chiral ammonium carbamate salts were quickly obtained by adding 1 atmosphere of CO2 gas to chiral silylated amines, easily prepared at gram scale and in some steps from natural amino acids as bio-renewable substrates. Some physical properties of these reversible chiral ionic liquids such as reversibility temperature, thermal degradation, miscibility, and stability have been determined. The spectroscopic characteristics of the silylated amine and ionic liquid states have also been compared. The properties of reversibility, chirality, and ease of preparation should make these silylamine-ionic liquid phases as promising solvents and/or catalysts for several applications, especially in asymmetric catalysis fields.

A stereoselective [4+ 2] annulation of acyclic all-carbon tetrasubstituted alkenes with allenoates was described. The reaction with DABCO proceeded smoothly leading to the formation of highly functionalized 4H-pyran derivatives in good yields. We have also reported first beta-ICD-catalyzed [4+ 2] annulation affording functionalized enantioenriched 2H-pyran derivatives bearing a chiral all-carbon quaternary center.

Phosphine–thiourea based-organocatalysts derived from l-proline promoted C−N or C−S bond formation of tert-butoxycarbonyloxy-Morita—Baylis—Hillman adducts with phthalimide or alkyl thiols, respectively. Good yields and enantioselectivities up to 93 % were achieved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

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.

β‐Amino alcohol and diamine ligands were prepared from isosorbide as a chiral renewable resource. The efficiencies of these ligands were evaluated for the metal‐catalyzed enantioselective ethylation of aldehydes and the alkynylation of aldimines.

A novel class of thiourea-phosphine was prepared from L-Proline as a chiral renewable resource. The original structure of the chiral framework offers an interesting potential to the construction of bifunctional organocatalysts for asymmetric transformations.

N-substituted S-perfluoroalkylated sulfoximines were synthesized from the NH sulfoximines either by a copper coupling reaction with aryl halides or by a reaction with electrophilic substrates. The procedure allowed the preparation of N,N′-bridged bis sulfoximines and of thioureas. The potential of these new sulfoximines was evaluated in different catalytic processes.

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.

A short and flexible procedure for the preparation of seven chiral azolinium and five functionalized chiral azolinium salts, precursors to N-heterocyclic carbenes, derived from L-proline has been developed. Moderate to good overall yields were obtained. Some NHC dimers and thiones were isolated. X-ray crystal structure determinations of two [Rh-NHC] complexes were also reported.