Abstract During the last few years, synthetic methods based on phosphine organocatalysis have experienced extremely fast developments. This short overview is intended to demonstrate that these can afford suitable tools for constitution of either focused or diversity‐oriented‐synthesis (DOS) inspired libraries small molecules biological screening. It also reports selected examples where organocatalytic been used conveniently as key steps in formal total synthesis complex natural products....

Different enynols and propargyl derivatives were sumitted to radical hydrostannylation (Bu3SnH/AIBN), Pd(0)-catalyzed [Bu3SnH/Pd(0)], stannylcupration [Bu3Sn(R)CuCNLi2] conditions. Except for the stannylation reaction, high regio- stereoselective formation of vinyl- dienylstannanes are obtained. Results tentatively explained in terms steric Interactions between alkyne or enyne substituents palladium cuprate moieties different reaction intermediates.

Conjugated dienes, properly activated by electron-withdrawing groups on both ends, are shown to be suitable substrates for phosphine-promoted organocatalytic processes. Their reactions with imines, under phosphine catalysis, afford a new and efficient synthetic approach functionalized 3-pyrrolines.

Abstract The synthesis of highly functionalized heterocyclic spiranes has been carried out by [3+2] cyclizations between allenoates and enones, under phosphine catalysis. Excellent enantioselectivity levels ( ee s up to 99%) have attained in FerroPHANE‐promoted this class, leading chiral sulfides with unprecedented spiranic structures. corresponding sulfoxides obtained then via a subsequent, diastereoselective oxidation the prostereogenic sulfur centre.

Abstract This work deals with the development of a new family planar chiral phosphoric acids based on ferrocenophane/paracyclophane scaffold. The synthetic approach has been improved by taking advantage phosphorylating agent to access enantiomerically enriched via diastereomers separation. These have used as catalysts for enantioselective H‐transfer reduction α‐substituted quinolines Hantzsch esters. Optimization both catalyst and reductant allowed ee values in range 82–92% be attained...

G-quadruplex structures (G4) are promising anticancerous targets. A great number of small molecules targeting these have already been identified through biophysical methods. In cellulo, some them able to target either telomeric DNA and/or sequences involved in oncogene promotors, both resulting cancer cell death. However, only a few bind G4 irreversibly. Here we combine within the same molecule G4-binding agent PDC (pyridodicarboxamide) with N-heterocyclic carbene-platinum complex NHC-Pt for...

A complete strategy: The total synthesis of discodermolide relies on the elaboration syn–anti stereotriads linked to a Z-O-enecarbamate group, its direct transformation into terminal Z diene, and stereocontrolled generation trisubstituted double bond by dyotropic rearrangement (see scheme; OCb=N,N-diisopropylcarbamoyloxy). was achieved in 21 steps with 1.6 % overall yield. Discodermolide is polyketide natural product that first isolated 1990 from extracts rare Caribbean marine sponge...

The key structural feature of the new phosphoramidites is a paracyclophane scaffold in which two aryl rings are tethered by both 1,8-biphenylene unit and O-P-O bridge. Suitable substituents generate planar chirality. corresponding gold(I) complexes promote cycloisomerization prochiral nitrogen-tethered dienynes. These reactions afford bicyclo[4.1.0]heptene derivatives displaying three contiguous stereogenic centers, with very high diastereoselectivity up to 95 % ee.

HMF (5-hydroxymethylfurfural), a renewable raw material from biomass, was used as the starting to provide 5-aryl-4-hydroxymethyl-4-hydroxycyclopentenones with functionalized aryl groups. First, arylic substituents were added aldehyde moiety of under rhodium- or palladium-catalyzed 1,2-addition arylboronic acids, in mild conditions respect very sensitive reactivity. Subsequently, these non-symmetrical furan-2,5-dicarbinols, through Piancantelli rearrangement, provided desired cyclopentenones...

Tetrasubstituted 2‐carboalkoxy‐3‐substituted‐cyclohexenones are powerful building blocks for the synthesis of a variety bioactive target molecules. Their preparations requires multi‐steps sequence involving use stoichiometric quantities various reagents, while catalytic approaches limitited to trisubstituted cyclohexenones. We describe here an efficient approach based on gold(I)‐catalysis starting from unsymmetrical diynyl mono‐ester or symmetrical di‐ester substrates. The carbon chain...

An efficient and modulable total synthesis of discodermolide (DDM), a unique marine anticancer polyketide is described including related alternative synthetic approaches. Particularly notable the repeated application crotyltitanation reaction to yield homoallylic (Z)-O-ene-carbamate alcohols with excellent selectivity. Advantage was taken this not only for stereocontrolled building syn-anti methyl-hydroxy-methyl triads DDM, but also direct construction terminal (Z)-diene. Of particular...

Cyclic phosphoric acids displaying planar chiral paracyclophane structures, which include a 1,1′-ferrocenediyl unit, have been designed as new class of organocatalysts. Their synthesis, optical resolution, structural characterization and preliminary catalytic tests are reported.

Phosphoric acids with planar chiral paracyclophane scaffolds have been prepared in optically pure form starting from 1,8-dibromobiphenylene, by means of a phosphorodiamidate as the phosphorylating agent. Structural characterization and configurational assignment performed X-ray diffraction studies. The promote organocatalytic enantioselective H-transfer reduction α-arylquinolines up to 90% enantiomeric excess.

Abstract A new synthetic approach to hexahydroisoindol‐4‐ones is reported, based on the formal [3+2] cyclization reaction between N ‐arylsulfonylimines and cyclic conjugated dienes, under phosphine catalysis. Key substrates are 3‐vinylcyclohex‐2‐enones with electron‐withdrawing substituents (ester, amido, cyano, phosphoryl keto groups) exocyclic double bond, which afford three‐atom synthons for construction of pyrroline ring. Total syn stereoselectivity observed in these annulations. The...

The enantioselective H-transfer hydrogenation of quinoline by Hantzsch ester is a relevant example Brønsted acid catalyzed cascade reactions, with phosphoric being privileged catalyst. generally accepted mechanism points out the hydride transfer step as rate- and stereodetermining step, however computations based on these models do not totally fit experimental observations. We hereby present computational study that enlightens stereochemical outcome quantitatively reproduces enantiomeric...

Abstract This manuscript discloses the first use of chiral phosphates based on C2‐symmetric paracyclophane scaffolds as counterions in transition metal catalysis, showing that they may compare favorably with other known phosphates, such TRIP phosphate. The targeted catalytic reaction is a silver(I) promoted domino heterocyclization 2‐(1‐alkynyl)‐2‐alken‐1‐one derivatives, presence C ‐, or N ‐nucleophiles, which provides an efficient access to substituted bicyclic furans. Results show high...

Piancatelli rearrangement on substituted non-symmetrical furan-2,5-dicarbinols has been developed using an effective combination of microwave activation and Lewis acid catalyst.

Abstract This manuscript reports on a suitable method for the synthesis of paracyclophane type, ferrocene‐bridged chiral phosphoric acids, which bear silyl‐substituents their frameworks. These acids have been obtained easily in enantiomerically pure form, by taking advantage ( S )‐(1‐phenyl‐2‐cyanoethyl)phosphorodiamidite as phosphorylating agent. They used then catalysts aza‐Friedel‐Crafts reactions between indoles and imines, giving high catalytic activity up to 98% enantiomeric excess....

Bioactive NHC-transition metal complexes have shown promise as anti-cancer agents, but their potential use radiosensitizers has been neglected so far. We disclose here a new series of bimetallic platinum(II) displaying NHC-type bridging ligands, (bis-NHC)[trans-Pt(RNH2)I2]2, that synthesized via simple, two-step procedure. They display cytotoxicity in the micromolar range on cancerous cell lines, accumulate cells, and bind to genomic DNA, by inducing DNA damages. Notably, these demonstrate...

Abstract The new domino process disclosed here involves PBu 3 as both a nucleophilic and reducing agent. combines suitable electron‐poor dienes, N ‐tosylimines, tri‐ n ‐butylphosphane water. final products formally result from reduction of vinylogous aza ‐Morita–Baylis–Hillman adducts. reaction proceeds with an excellent stereochemical control the relative configurations newly created contiguous carbon centres.

Stannylcupration of alkyne 6 was performed using different proton sources such as phenols, alcohols and water; results showed that the cuprate reagent not affected during reaction. In all cases tested in presence a source, vinylstannane 10 corresponding to trans addition produced, while distal proximal isomers 8 9 resulting from cis were obtained good yield. The 8/9 ratio dependent on reaction temperature, acidity number equivalents source. This study also extended stannylcupration enynes...