Synthesis and Crystal Structure of β-Amino-α-Phenyl-α-Ferrocenylethanol

β-Amino-α-phenyl-α-ferrocenylethanol, FcC(OH)(Ph)CH₂NH₂ was prepared by the reduction of cyanohydrin trimethylsilyl ether of benzoylferrocene with lithium aluminum hydride. This new compound was characterized by elemental analysis, IR and ¹H NMR spectroscopy. The structure was also confirmed by a single crystal X-ray study. The compound crystallizes in monoclinic P2₁/c space group with unit cell dimensions: a = 12.5906(17), b = 5.9636(8), c = 19.8320(3) Å, β = 102.047(2)^∘, V = 1456.3(3) ų, Z = 4. The structure exhibits intra- and inter-molecular hydrogen bonding of the type N—H⋅ < eqid1 > ⋅O and O—H⋅ < eqid2 > ⋅N, respectively. The pattern of the inter-molecular hydrogen bonding interaction contains a 10-atom ring with two donors and two acceptors, showing a dimeric crystal packing.     

Synthesis and Reactivity of α-Bromo-4-(difluoromethylthio)acetophenone

A synthesis is reported for -bromo-4-difluoromethylthioacetophenone and the conditions for the condensation of this compound with 2-aminothiazole, 2-amino-5-chloropyridine, 2-amino-4,5-dihydro-3H-pyrrole, benzimidazoline-2-thione, oxadiazoline-2-thione, and thiourea were studied. S- and N-substituted azaheterocycles containing the 4-(difluoromethylthio)phenyl fragment were synthesized and characterized.     

Synthesis of ( )-5α-Hydroxy-β-selinene and (-)-5β-Hydroxy-β-selinene

Eudesmanederivativeshavebeendrawingconsiderableattentionduetotheirwidespectrumofbiologicalproperties,particularlyantifeedant,cellgroWthinhibitoryandplantgroWthregulatingactivitiesl'2.Recently,twoepimericeudesmanederivatives( )-5a-hydroxy-6-selinene1and(-)-56-hydroxy-6-selinene2wereisolated3fromtheaerialpartsofCSubtraPicaFMell.,andtheirstructuresweredeterminedbyspectroscopicmethods.Herein,wereportafacilesynthesisofbothtwodiastereomers1and2from( )-dihydrocarvone3infivesteps,usingtheregioselect…     

Synthesis and Reactivity of β-Carboline-Hydantoin Systems

The synthesis of 2,5-disubstituted 1,3-dioxo-6H-1,2,3,5,11,11a-hexahydroimidazo[1, 5-b]-β-3a-y and the reduction of carbolines 3m-r with different amounts of lithium aluminium hydride is described.     

Facile Synthesis of 7-Amino-1,2,3,4-tetrahydro-β-carboline

Abstract

7-Amino-1,2,3,4-tetrahydro-β-carboline has been prepared by a short efficient synthetic sequence based on a regioselective nitration of a fully protected 1,2,3,4-tetrahydro-β-carboline.     

Synthesis,Structure and Reactivity of Lanthanocene Complexes

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃｈｅｍｉｓｔｒｙｏｆｏｒｇａｎｏｌａｎｔｈａｎｉｄｅｓｈａｓｅｘｐｅｒｉｅｎｃｅｄｅｘｔｒｅｍｅｌｙｉｍｐｏｒｔａｎｔｄｅｖｅｌｏｐｍｅｎｔｓｄｕｒｉｎｇｔｈｅｌａｓｔｔｗｏｄｅｃａｄｅｓ ,ａｎｄｎｕｍｅｒｏｕｓｕｎｕｓｕａｌｃｏｍｐｏｕｎｄｓｗｉｔｈｕｎｐｒｅｃｅ ｄｅｎｔｅｄｓｔｒｕｃｔｕｒｅｓａｎｄｕｎｉｑｕｅｒｅａｃｔｉｖｉｔｙｐａｔｔｅｒｎｓｈａｖｅｂｅｅｎｐｒｅｐａｒｅｄ .1ＯｒｇａｎｏｌａｎｔｈａｎｉｄｅｃｏｍｐｏｕｎｄｓｃｏｎｔａｉｎｉｎｇＬｎ—Ｃ ,…     

Synthesis of β-Amino-α,α-dichloro Sulfones from Vinyl Sulfones

β-amino-α,α-dichloro sulfones 3 are prepared by the reaction of vinyl sulfone 1 with primary or secondary amines 2in the presence of CCI₄ and NaH.     

α-Radical Phosphines: Synthesis,Structure, and Reactivity

A series of phosphines featuring a persistent radical were synthesized in two steps by condensation of dialkyl-/diarylchlorophosphines with stable cyclic (alkyl)(amino)carbenes (cAACs) followed by one-electron reduction of the corresponding cationic intermediates. Structural, spectroscopic, and computational data indicate that the spin density in these phosphines is mainly localized on the original carbene carbon from the cAAC fragment; thus, it remains in the α-position with respect to the central phosphorus atom. The potential of these α-radical phosphines to serve as spin-labeled ligands is demonstrated through the preparation of several Au^I derivatives, which were also structurally characterized by single-crystal X-ray diffraction.     

3-Amino-4-(α-nitroalkyl-ONN-azoxy)furazans and some of their derivatives

Synthetic procedures towards 3-amino-4-(a-nitroalkyl-ONN-azoxy)furazans and their derivatives involving nucleophilic displacement of the nitro group of 3-nitro-4-(a-nitroalkyl-ONN-azoxy)furazans on treatment with ammonia, primary and secondary amines, including diamines, were developed.     

Synthesis and hetero-Diels-Alder reactions of (E)-α-perfluoroalkanesulfonyl-α,β-unsaturated ketones

Catalyzed by ammonium acetate, the Knoevenagel reactions of β-keto perfluoroalkanesulfones 1 with aromatic aldehydes 2 afforded α-perfluoroalkanesulfonyl-α,β-unsaturated ketones 4 in moderate to good yields. The possible mechanism for the reactions was proposed. These fluorine-containing α,β-unsaturated ketones, which are electron-poor 1-oxa-1,3-butadienes, could be used in inverse electron demand hetero Diels-Alder (HDA) reaction with electron-rich olefins to give tetrasubstituted dihydropyrans 6 in quantitative yields.     

First Total Synthesis of 3α,4α-Oxidoagarofuran and (-)-3β,4α-Dihydroxy-β-dihydroagarofuran

The first stereoselective total synthesis of (–)-3β, 4α-dihydroxy-β-dihydroagarofuran (1) and 3α, 4α-oxidoagarofuran (2) has been described. The key step is the epoxidation of α-agarofuran (6) with dimethyldioxirane.     

Synthesis and Crystal Structure of O,O-Dimethyl-N-(β-triphenylgermanyl)propionyl-α- aminobenzylphosphonates

1 INTRODUCTION Both β-triphenylgermanyl propionic acid and its derivatives have recently attracted a great deal of attention due to their strong anti-inflammatory as well as antibiotic properties[1~3]. α-aminobenzyl- phosphonates are also reported to exhibit diverse biological activities[4~6].It is conceivable that the incorporation of the two moieties into one structural unit might produce an unexpected effect on the activity of such a compound, and the studies on this type of novel s…     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

The synthesis of a new crosslinked polymer by reaction of , -polyasparthydrazide and glutaraldehyde is reported. Different crosslinking degrees were obtained by varying the ratio between the aldehyde and the starting polymer. The crosslinked polymer was characterized by water swelling tests and thermal analysis. In particular, the crosslinking density and its effects on the glass transition temperature of the material were studied. Finally, the microstructure of the obtained polymer was observed using scanning electron microscopy.     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

, -polyasparthydrazide (PAHy) was crosslinked by glutaraldehyde to form water-swellable materials possessing a three-dimensional molecular network. Different crosslinking degrees were prepared varying glutaraldehyde/PAHy ratio and samples containing 5-fluorouracil were obtained by incorporating the drug into the polymer networks during the crosslinking reaction. All samples were characterized by swelling tests, thermal, x-ray and SEM analysis. Their microstructure was observed through scanning electron microscopy. Furthermore, for samples containing the anticancer drug,in vitro release studies were performed in pH 7.4 buffer solution.     

Synthesis and conformational studies of chiral meso-(α,β-unsaturated)-porphyrins

We describe a method to improve the yield and the kinetics of the difficult syntheses of α,β-unsaturated porphyrins, which enabled us to obtain a new chiral porphyrin derived from (S)-(−)-perillaldehyde in a 6% yield. Variable temperature NMR experiments on the free base, the zinc(II) and the nickel(II) complexes showed that two distinct and consecutive dynamic processes linked with the meso substituents rotation occurred. These processes can be analyzed as an evolution of the conformer composition upon temperature change. Higher values are found for the free energies of rotation of the substituent (measured by variable temperature ¹H NMR) compared to those of other equivalent porphyrins like meso-tetraphenyl porphyrin or meso-tetracyclohexyl porphyrin.     

Synthesis,Stability and Reactivity of α-Fluorinated Azidoalkanes

Organic α-fluorinated azidoalkanes appeared in the literature for the first time half a century ago. However, for a long time they remained undeveloped and were regarded as chemical curiosities. Recent advances in the preparation of α-fluorinated azidoalkanes as well as studies on their stability and reactivity opened up their broader synthetic potential for the preparation of valuable fluorinated and non-fluorinated compounds.     

Synthesis of pyrazolines by the reactions ofα,β-enones with diazomethane and hydrazines (review)

The first representatives of pyrazolines were synthesized in the last century. These nitrogen-containing heterocyclic compounds became important in the development of different bioactive substances. For this reason, various procedures have been worked out for their synthesis. In the present article we summarize those synthetic methods providing 1- or 2-pyrazolines by the reactions of ,-unsaturated ketones with diazomethane or hydrazine derivatives.Department of Organic Chemistry, Kossuth Lajos University, Egyetem ter I, H 4010 Debrecen, Hungary. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 747–759, June, 1997.     

A New Synthesis of Methyl 3-Amino-3,4-dideoxy-β-D-xylo-hexopyranoside

Abstract

Benzylidenation of methyl β-D-glucopyranoside, followed by selective 3-O-tosylation, reductive acetal opening, chlorination, radical deoxygenation and transesterification, afforded methyl 2,3-anhydro-6-O-benzyl-4-deoxy-β-D-ribo-hexopyranoside 8. Subsequent epoxide opening with NaN₃ and catalytic hydrogenation led to the title compound.     

Conversion of Epiandrosterone Into 17β-Amino-5α-androstane

A new method for synthesizing 17-amino-5-androstane was developed based on tigogenin. The configuration at C-17 was proved by PMR.