The effect of Lewis acids on the catalytic activity [Mn2(μ-O)3(TMTACN)2](PF6)2 in epoxidation styrenes using hydrogen peroxide as oxidant has shown that addition Sc(OTf)3 at low loading results a very significant increase efficiency catalyst and reduction reaction time to only 3 minutes most cases.

A new approach to polymeric supports useful for the immobilization of aldehydes and ketones via hydrazone linkers is reported. The strategy gives with better properties effective synthesis all previously used alkylation anchored as hydrazones. In contrast other approaches, also provided a polymer an economical C2 spacer linker. were 3-pentanone, acetone, N-benzylpiperidone, hexanal 3-phenylpropanal in form their polymer-supported hydrazones subjected α-alkylation (LDA/RX) followed by acidic,...

Polymer-anchored (Merrifield, trityl chloride, Wang p-nitrophenyl carbonate and triazene supports) nortropinone, or N-protected nortropinone derivatives in solution, were subjected to deprotonation with LDA chiral lithium amides, the resulting enolates trapped an aldehyde. The aldols obtained moderate good yields (44-84%) enantioselectivities (44-86% ee). Keywords: Aldol reaction, polymer support, solid-phase synthesis, amide,

Direct aldol reactions of tropinone and granatanone (pseudopelletierine) with aromatic aldehydes were promoted by the presence water. The anti–syn-diastereoselectivity depended on amount water used or possibility product precipitation from reaction mixture. Some showed excellent atom economy, a low E factor, high diastereoselectivity (up to 98%). In several cases 'seeding' anti isomer, induce deposition solid products, improved conversion 1.8 times) anti–syn ratio 98 : 2). applicability...

Several N-substituted nortropane and norgranatane derivatives were synthesised from tropinone granatanone. The equilibrium distributions of the axial equatorial N-invertomers free amine forms prepared products in methanol their protonated (hydrochlorides) water studied by low-temperature room-temperature NMR spectroscopy. Theoretical gas phase, solvents calculated using DFT methods compared with inverse gated 13C experiments. calculations provided results reasonable agreement experimental...

Several chiral secondary <i>N</i>-benzhydrylamines were synthesized in good yields (68–92%) without racemization by the direct alkylation of amines with benzhydryl chloride under solvent-free conditions. Using conditions (<i>R</i>)-<i>N</i>-benzhydryl-1-phenylethylamine was obtained highest yield (92%), purified on ion-exchange resin, and converted to its hydrochloride salt. The resulting amine transformed into lithium amide/lithium mixture used asymmetric deprotonations <i>N</i>-benzyl...

The preparation of new solid supports with hydrazine anchoring groups and their application to solid-phase synthesis ketones primary amines are described. were used for immobilization ketones, 4-tert-butylcyclohexanone, pentan-3-one, acetone, N-methylpiperidone, N-benzylpiperidone, tropinone in the form hydrazones. polymer-supported hydrazones subjected deprotonation/alkylation procedure (LDA/RX) once or twice. resulting alkylated products cleaved off support on treatment trifluoroacetic...

The preparation and application of new solid supports with chiral linkers, analogues SAMP hydrazine on solid-phase, are described. were used for immobilization ketones (diethylketone, cyclohexanone, 4-tert-butylcyclohexanone), diastereoselective alkylation formed ketone hydrazones. enantiomeric purities cleaved α-alkylated ranged from 10 to 73%. use lithium amides metalation hydrazones t-butylcyclohexanone increased the excess alkylated product by 25−47%.

The relative configurations of tert-butyldimethylsilyl (TBDMS) ethers all four diastereomers the aldols tropinone (8-methyl-8-azabicyclo[3.2.1]octan-3-one), as well granatanone (9-methyl-9-azabicyclo[3.3.1]nonan-3-one), were determined from NMR data, and observed interconversion (exo,anti to endo,syn exo,syn endo,anti). exo forms invert endo isomers in presence silica gel. configuration a new isomer aldol accessible synthetically through direct solventless reaction benzaldehyde water was by...

The exo , anti / syn -diastereoselectivity of water promoted direct aldol reactions tropinone and granatanone (pseudopelletierine) is strongly dependent on the amount added aromatic aldehyde used. DFT methods were applied to calculate free energies enols, transition states, isomeric products. A theoretical model was verified by comparison results from several functionals with experiments. 6-31g(d)/CPCM method proved most suited problem, although all tested predicted similar trends. Explicit...

The title compounds, C 21 H 22 BrNO 2 , are isomeric 8-benzyl-2-[(4-bromophenyl)(hydroxy)methyl]-8-azabicyclo[3.2.1]octan-3-ones. Compound (I), the (±)- exo syn -(1 RS ,2 SR ,5 ,9 ) isomer, crystallizes in hexagonal space group R \overline{3}, while compounds (II) [the (+)- anti S isomer] and (III) crystallize orthorhombic groups P 1 Pna respectively. absolute configuration was determined for enantiomerically pure (II). For noncentrosymmetric crystal of (III), its structure established. In...

Seven selected chiral mono-, di-, and tridentate amines supported on insoluble polymer were effectively prepared from corresponding primary or secondary amino alcohols Merrifield resin. The reaction of the polymer-supported with excess n-butyllithium gave lithium amide bases, which tested in aldol reactions tropinone benzaldehyde. deprotonation carried out without separation enolate reagents. Using procedure reagent different results obtained addition LiCl despite fact that aggregate...

Abstract (R)‐N‐benzhydryl‐1‐phenylethylamine is utilized as chiral auxiliary in asymmetric deprotonations of N‐benzyl analogues tropinone and granatanone.