• Issue

    European Journal of Organic Chemistry: Volume 2009, Issue 12

    1819-2009
    April 2009

Graphical Abstract

Graphical Abstract: Eur. J. Org. Chem. 12/2009

  • Pages: 1819-1825
  • First Published: 30 March 2009

Microreview

Julia–Kocienski Olefination

Mechanistic Manifold and New Developments of the Julia–Kocienski Reaction

  • Pages: 1831-1844
  • First Published: 30 March 2009
Description unavailable

The olefination toolbox, already well fitted with heterocyclic sulfones, has recently been further enriched with new electron-poor sulfones. Moreover, results garnered over the past two decades seem to confirm the mechanistic assumptions put forward by S. Julia since his seminal discovery of the Julia–Kocienski olefination.

Short Communications

Organocatalysis

Desymmetrization of meso-N-Acylaziridines with Benzenethiols Promoted by α,α-Diaryl-L-prolinols

  • Pages: 1845-1848
  • First Published: 30 March 2009
Description unavailable

The desymmetrization of meso-N-acylaziridines with benzenethiols is provided by using commercially available α,α-L-diphenylprolinol as the organocatalyst. The products are obtained in good yield and moderate enantiontioselectivity, which can be improved to high levels (>90 % ee) by a single recrystallization.

Isothiocyanate Synthesis

Molecular Iodine Mediated Preparation of Isothiocyanates from Dithiocarbamic Acid Salts

  • Pages: 1849-1851
  • First Published: 30 March 2009
Description unavailable

We have developed perhaps the most efficient and simple, environmentally benign method for the preparation of isothiocyanates from the corresponding dithiocarbamic acid salts by using molecular iodine. The reagent is easily available and nontoxic, and the precipitated sulfur can be removed easily; hence, this method is most suitable for large-scale synthesis.

Synthesis of Imidazopyrazines

Cyclic Endiamino Peptides: A New Synthesis of Imidazopyrazines

  • Pages: 1852-1854
  • First Published: 30 March 2009
Description unavailable

Cyclisation of enol-tosylated tripeptides afforded imidazopyrazines and cyclic endiamino peptides. A possible mechanism is suggested.

Redox-Controlled Switching

Redox-Controlled Dihydroazulene-Vinylheptafulvene Photoswitch Incorporating Tetrathiafulvalene

  • Pages: 1855-1858
  • First Published: 30 March 2009
Description unavailable

A novel dihydroazulene (DHA)–tetrathiafulvalene (TTF) conjugate has been synthesized. The photoswitching efficiency to the vinylheptafulvene (VHF) isomer is foundto depend on the redox-state of the TTF unit (0 or +1), while the thermal ring closure of VHF to DHA is unaffected.

Aqueous Petasis Reaction

Water: A Suitable Medium for the Petasis Borono-Mannich Reaction

  • Pages: 1859-1863
  • First Published: 30 March 2009
Description unavailable

Water was used for the first time as the solvent in the Petasis borono-Mannich reaction, and several alkylaminophenols and 2H-chromenes were obtained in considerably high yields. The reaction mechanism was studied by DFT calculations, and the results obtained corroborate the solvent effect experimentally observed.

Aerobic Homocoupling

Homocoupling of Arylboronic Acids Catalyzed by 1,10-Phenanthroline-Ligated Copper Complexes in Air

  • Pages: 1864-1867
  • First Published: 30 March 2009
Description unavailable

The homocoupling of arylboronic acids was achieved at ambient temperature in air with 1,10-phenanthroline-ligated binuclear (μ-hydroxido)copper complex as a catalyst. This method tolerates various substituentson the arylboronic acids. As a result, 25 symmetrical biaryls were obtained from readily available arylboronic acids in 19–92 % isolated yield.

Gel Formation by Acenes

2,3-Di-n-undecylanthracene and 2,3-Di-n-decyloxyanthracene (DDOA) – on the Connecting Link between the Aromatic Substrate and the Aliphatic Chain in Self-Assembling Systems

  • Pages: 1868-1870
  • First Published: 30 March 2009
Description unavailable

The gelling properties of linear acenes 1 (Alk = C10H21) depend critically on the atom connecting the aliphatic and the aromatic part of the molecules. Whereas in the case of X = O supergelators result, with X = CH2 no gelling is observed at all.

Full Papers

Subphthalocyanine Chemistry

Peripheral Functionalization of Subphthalocyanines

  • Pages: 1871-1879
  • First Published: 30 March 2009
Description unavailable

Some useful procedures for the incorporation of diverse functional groups in the periphery of the subphthalocyanine macrocycle are described.

Carbanucleosides

Click Azide-Alkyne Cycloaddition for the Synthesis of D-(–)-1,4-Disubstituted Triazolo-Carbanucleosides

  • Pages: 1880-1888
  • First Published: 30 March 2009
Description unavailable

The synthesis of D-(–)-1,4-disubstituted triazolo-carbanucleoside derivatives 1621 is achieved using high yielding protocolsbased on ring-closing metathesis and copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC).

Asymmetric Catalysis

The Synthesis of New HetPHOX Ligands and Their Application to the Intermolecular Asymmetric Heck Reaction

  • Pages: 1889-1895
  • First Published: 30 March 2009
Description unavailable

The synthesis of six members of the HetPHOX P,N ligand class, with variation at phosphorus and the oxazoline 4-substituent, has been developed. The ligands provide good levels of enantioselection (eevalues up to 95 %) in a prototypical Pd-catalyzed intermolecular asymmetric Heck reaction employing 2,3-dihydrofuran as substrate. In addition, the kinetic product was favoured up to 98:2.

Pheromone Synthesis

A Facile Synthesis of Both Enantiomers of 6-Acetoxy-5-hexadecanolide, a Major Component of Mosquito Oviposition Attractant Pheromones

  • Pages: 1896-1901
  • First Published: 30 March 2009
Description unavailable

The mosquito attractant pheromone was synthesized in overall 28 % yield by using Sharpless asymmetric epoxidation andZrCl4-catalyzed cyclic acetal formation as key steps.

Water-Soluble Nitroxides

The Synthesis of Novel Isoindoline Nitroxides Bearing Water-Solubilising Functionality

  • Pages: 1902-1915
  • First Published: 30 March 2009
Description unavailable

A number of novel tetramethyl- and tetraethylisoindoline nitroxides possessing water-solubilising functionalities were synthesised. The increased steric bulk of the tetraethyl structures should limit bio-reduction and these compounds may have potential as antioxidants.

Inherently Chiral Calixarenes

Synthesis of an Inherently Chiral Calix[4]arene Amino Acid and Its Derivatives: Their Application to Asymmetric Reactions as Organocatalysts

  • Pages: 1916-1924
  • First Published: 30 March 2009
Description unavailable

The synthesis of an inherently chiral calix[4]arene amino acid as a chiral building block has been achieved. Different types of optically pure calix[4]arene amino acid derivatives were obtained and these were applied to asymmetric reactions as organocatalysts.

Facile Aza-Claisen Rearrangement

Facile Aza-Claisen Rearrangement of Glycals: Application in the Synthesis of 1-Deoxy-L-iminosugars

  • Pages: 1925-1933
  • First Published: 30 March 2009
Description unavailable

L-allo-Deoxynojirimycin (4) and two new C-5-(hydroxymethyl) analogues of L-altro-deoxynojirimycin and L-ido-deoxynojirimycin, 5 and 6, respectively, have been synthesized by a strategy that involves an aza-Claisen rearrangement and an intramolecular N-heterocyclization as the key steps.

Domino Reactions

Domino or Single-Step Tsuji–Trost/Heck Reactions and Their Application in the Synthesis of 3-Benzazepines and Azepino[4,5-b]indole Ring Systems

  • Pages: 1934-1943
  • First Published: 30 March 2009
Description unavailable

3-Benzazepines and azepino[4,5-b]indoles are readily prepared in one pot by utilizing domino Tsuji–Trost/Heck reactions. Through this methodology, and the single-step equivalent, complex 6-7-6 and 6-5-7ring heterocycles have been prepared. In addition, a domino Heck/Heck sequence of reactions that produces the azepinobenzindolizine tetracyclic ring system from N-diallylated precursors is described.

Natural Product Analogues

Synthesis of AE and BE Ring Analogues of the Alkaloid Methyllycaconitine

  • Pages: 1944-1960
  • First Published: 30 March 2009
Description unavailable

The synthesis of AE and BE analogues of the alkaloid methyllycaconitine is reported. The analogues contain the two key 2-(2-methylmaleimido)benzoate ester pharmacophores embedded in an octahydroquinoline motif that mimics the EB-rings of methyllycaconitine.

Hydrosilylation

Influence of Lewis Acid and Solvent in the Hydrosilylation of Aldehydes and Ketones with Et3SiH; Tris(pentafluorophenyl)borane B(C6F5)3 versus Metal Triflates [M(OTf)3; M = Sc, Bi, Ga, and Al] – Mechanistic Implications

  • Pages: 1961-1966
  • First Published: 30 March 2009
Description unavailable

The Et3SiH/M(OTf)3 (M = Sc, Bi, Ga, Al) systems exhibit very different chemoselectivity as compared to the Et3SiH/B(C6F5)3 system in the reaction with aromatic aldehydes and ketones.

Regioselective Enzymatic Deprotection

A Versatile Synthesis of 5′-Functionalized Nucleosides Through Regioselective Enzymatic Hydrolysis of Their Peracetylated Precursors

  • Pages: 1967-1975
  • First Published: 30 March 2009
Description unavailable

Screening of immobilized lipases against natural and modified peracetylated nucleosides provided a set of biocatalysts with different regioselectivities. Selectively deprotected nucleosides were prepared with theselipases by enzymatic reaction and were then used for the chemo-enzymatic synthesis of 5′-functionalized nucleosides and mononucleotides in high yields andpurities.

Functional Dyes

Tris[oligo(1,4-phenylenevinylene)]methylium Dyes

  • Pages: 1976-1983
  • First Published: 30 March 2009
Description unavailable

Tris[oligo(1,4-phenylenevinylene)]carbinols2 form methylium dyes, the absorptions ofwhich depend strongly on the different protonation processes for n = 1 and n > 1.

Calystegines, Azasugars

Total Synthesis of 3-O-Benzyl-1,3,5-tri-epi-calystegine B2 from L-Sorbose

  • Pages: 1984-1993
  • First Published: 30 March 2009
Description unavailable

The 3-O-benzyl derivative of the polyhydroxylated nor-tropane alkaloid 1,3,5-tri-epi-calystegine B2 was prepared from L-sorboseby a Wittig and magnesium-mediated alkylation methodology, followed by a ring-closing olefin metathesis (RCM) reaction.

One-Pot β-Lactam Synthesis

Application of the Octacarbonyldicobalt-Catalyzed Carbonylation of Ethyl Diazoacetate for the One-Pot Synthesis of N-tert-Butyl-trans-α-ethoxycarbonyl-β-phenyl-β-lactam

  • Pages: 1994-2002
  • First Published: 30 March 2009
Description unavailable

The effective one-pot synthesis of N-tert-butyl-trans-α-ethoxycarbonyl-β-phenyl-β-lactam by the octacarbonyldicobalt-catalyzed carbonylation of ethyl diazoacetate in the presence of N-tert-butylbenzaldimine is described.

Substituted Dihydropyranones

[4+2] Annulation – Convenient Synthesis of Substituted Dihydropyranones in Aqueous Media

  • Pages: 2003-2009
  • First Published: 30 March 2009
Description unavailable

A series of substituted dihydropyranones were synthesized by a formal [4+2] annulation of α-acetyl ketene S,S-acetals with aldehydes in the presence of NaOH in water.