Highly efficient gold(I)-catalyzed Overman rearrangement in water

• Dong Xing and
• Dan Yang

Beilstein J. Org. Chem. 2011, 7, 781–785, doi:10.3762/bjoc.7.88

• hydroxy groups (1h and 1i) efficiently underwent the desired rearrangement to afford the corresponding products, which are precursors for the synthesis of a variety of β-substituted β-amino alcohols (Table 2, entries 8 and 9). Compound 2j was also obtained in 71% yield under the reaction conditions from

Metathesis access to monocyclic iminocyclitol-based therapeutic agents

• Ileana Dragutan,
• Valerian Dragutan,
• Carmen Mitan,
• Hermanus C.M. Vosloo,
• Lionel Delaude and
• Albert Demonceau

Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81

• the 6-membered N-heterocycle in 133. Protection of the amino alcohols trans-132 and cis-132, as the corresponding trans and cis oxazolidinones, afforded a mixture of diastereomers that were not separable on silica gel. After effecting RCM (2nd-generation Grubbs catalyst 5, 5 mol %) on this mixture

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

• Michael North and
• Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

• and β-amino alcohols [2] (Scheme 1). Asymmetric cyanohydrin synthesis can be achieved by the use of a suitable chiral catalyst, and a wide range of catalysts have been found to catalyse this reaction including enzymes [3][4], organocatalysts [5][6] and metal-based catalysts [1]. All of the most

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

• bonding toward the R-enantiomer of phenylalanine methyl ester hydrochloride with KR/KS of 6.87 in CDCl3 with 0.25% CD3OD. The binding constants were far lower as in the former examples. Related macrocycles 30 with diamide-diester groups derived from dimethyloxalate and amino alcohols (Figure 16) also

• conditions for chiral separation of amines and amino alcohols [180]. The azophenolic crown ether was a versatile and a highly enantioselective host for their chiral separation by reactive extraction. Transport from a basic aqueous solution of the racemic mixture in CH2Cl2 and toluene was followed by UV–vis

• )-46b showed an even more intensive color change induced by a wide range of (S)-α-amino alcohols compared to the corresponding (R)-α-amino alcohols. The function, mechanisms and applicability of phenolphthalein crown systems have been recently summarized by Tsubaki [186]. Ditopic receptors can consist

Concise methods for the synthesis of chiral polyoxazolines and their application in asymmetric hydrosilylation

• Wei Jie Li,
• Zun Le Xu and
• Sheng Xiang Qiu

Beilstein J. Org. Chem. 2010, 6, No. 29, doi:10.3762/bjoc.6.29

• , Sun Yat-Sen University, 135 Xingang West Road, Haizhou District, Guangzhou 510275, China 10.3762/bjoc.6.29 Abstract Seven polyoxazoline ligands were synthesized in high yield in a one-pot reaction by heating polycarboxylic acids or their esters and chiral β-amino alcohols under reflux with

• potential, until now, only a few polyoxazoline ligands have been reported in the literature due to synthetic difficulties. In general, the syntheses of polyoxazolines from polycarboxylic acids or polycarboxylates and chiral amino alcohols are carried out via poly(β-hydroxyamide)s as intermediates, followed

• required for the preparation of polyoxazoline ligands. In the present study, we report the results of heating polycarboxylic acids or their esters with chiral β-amino alcohols under reflux conditions with the simultaneous removal of water or the alcohol produced in the reaction in a one-step process for

Palladium- catalyzed cross coupling reactions of 4-bromo- 6H-1,2-oxazines

• Reinhold Zimmer,
• Elmar Schmidt,
• Michal Andrä,
• Marcel-Antoine Duhs,
• Igor Linder and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2009, 5, No. 44, doi:10.3762/bjoc.5.44

• derivatives constitute a versatile class of N,O heterocycles [1][2][3][4][5][6][7][8][9][10][11][12][13]. Considerable attention has been paid to 6H-1,2-oxazines 1 bearing a C-4,C-5-double bond [14][15][16][17][18], which are useful intermediates in the synthesis of γ-lactams [19], γ-amino acids [20], amino

• alcohols [20], aziridines [21], pyrrolizidines [22], and pyrrolidine derivatives [15][23][24]. In the context of our ongoing exploration of the synthetic potential of these heterocycles we were interested to modify the substitution pattern of the C-4,C-5 double bond of 6H-1,2-oxazines [25][26][27]. Herein

(−)-Complanine, an inflammatory substance of marine fireworm: a synthetic study

• Kazuhiko Nakamura,
• Yu Tachikawa and
• Daisuke Uemura

Beilstein J. Org. Chem. 2009, 5, No. 12, doi:10.3762/bjoc.5.12

• absolute structure of complanine was unambiguously determined by means of synthetic methodology by a “chiral synthon” approach. Related amino alcohols possessing olefins from marine natural resources have been identified [3][4], but synthetic studies of these compounds have not been reported. Results and

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• variable spacers (Figure 1). Previously, we have prepared a series of glycosylated asparaginic acid building blocks containing as spacers either simple alkyl chains [1], or amino alcohols [2][3]. Such building blocks have been shown to be well suited for combinatorial solid phase or spot synthesis of

Flexible synthetic routes to poison- frog alkaloids of the 5,8-disubstituted indolizidine- class I: synthesis of common lactam chiral building blocks and application to the synthesis of (-)-203A, (-)-205A, and (-)-219F

• Naoki Toyooka,
• Dejun Zhou,
• Hideo Nemoto,
• H. Martin Garraffo,
• Thomas F. Spande and
• John W. Daly

Beilstein J. Org. Chem. 2007, 3, No. 29, doi:10.1186/1860-5397-3-29

• then treatment of the resulting deblocked amino alcohols with trimethylaluminum under Weinreb's conditions [21] gave rise to the lactams 1 and 2 in 71% and 68% overall yields, respectively. To demonstrate the utility of the chiral lactam building blocks, we conducted the total synthesis of

Reactions of glycidyl derivatives with ambident nucleophiles; part 2: amino acid derivatives

• Gerald Dyker,
• Andreas Thöne and
• Gerald Henkel

Beilstein J. Org. Chem. 2007, 3, No. 28, doi:10.1186/1860-5397-3-28

• ) no cyclization products were obtained. Finally we succeeded in achieving a cyclization by a two-step procedure: the cobalt-catalyzed addition of electron-rich anilines 6 according to Iqbal [9] let to amino alcohols 7, which then cyclized in basic medium (NaH in DMF or THF), either to give 7-membered