Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support

• Jagdish D. Tibhe,
• Hui Fu,
• Timothy Noël,
• Qi Wang,
• Jan Meuldijk and
• Volker Hessel

Beilstein J. Org. Chem. 2013, 9, 2168–2179, doi:10.3762/bjoc.9.254

• development of an enzymatic bioreaction and found that the dynamics of a biochemical reaction can be studied in a few seconds [35]. Although many promising routes have been developed for the synthesis of chiral α-amino alcohols, these often depend on the use of toxic and expensive chiral ligands coupled to

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• including cinchona alkaloid derivatives, chiral phosphoric acids, chiral amino alcohols, chiral thioureas, chiral guanidines, and chiral 1,2,3-triazolium chlorides. In this review, the research work of enantioselective desymmetrization of meso-aziridines is organized into sections according to the employed

• activation mechanism of this desymmetrization was proposed. Chiral amino alcohols Lattanzi and colleagues [49] have also discovered the desymmetrization of meso-N-acylaziridines with benzenethiols in the presence of α,α-diaryl-L-prolinols (Figure 6, OC-22 to OC-25) to afford the products in good yields and

• -aziridines are plentiful and can be found in a diverse set of privileged structures, including cinchona alkaloids-based PTCs, L-proline-derived amino alcohols, chiral phosphorous acids, chiral thioureas, chiral guanidines, and chiral 1,2,3-triazolium chlorides. But for the desymmetrization of meso-epoxides

Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

• Sándor B. Ötvös,
• Ádám Georgiádes,
• István M. Mándity,
• Lóránd Kiss and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1508–1516, doi:10.3762/bjoc.9.172

• bioactive agents with anticancer, antibacterial, antiviral or analgesic effects (Figure 2) [25][26]. The alicyclic β-amino acids are key intermediates for the synthesis of a series of pharmaceutically relevant products [27], such as amino esters, amino alcohols, azides and heterocycles. Moreover, they are

Titanium-mediated reductive cross-coupling reactions of imines with terminal alkynes: An efficient route for the synthesis of stereodefined allylic amines

• Kebin Mao,
• Guoqin Fan,
• Yuanhong Liu,
• Shi Li,
• Xu You and
• Dan Liu

Beilstein J. Org. Chem. 2013, 9, 621–627, doi:10.3762/bjoc.9.69

• 1,2-amino alcohols [39]. These results prompted us to study the cross-coupling of imines with terminal alkynes by using the Ti(OiPr)4/2 c-C5H9MgCl reagent. In this paper, we describe the detailed results of these reactions (Scheme 1). Results and Discussion Synthesis of allylic amines by reductive

Efficient synthesis of β’-amino-α,β-unsaturated ketones

• Isabelle Abrunhosa-Thomas,
• Aurélie Plas,
• Nishanth Kandepedu,
• Pierre Chalard and
• Yves Troin

Beilstein J. Org. Chem. 2013, 9, 486–495, doi:10.3762/bjoc.9.52

• incorporating β-amino ketone functionality are prevalent in many natural products of biological importance [1]. This versatile synthon has been extensively used in the construction of β-amino acids [2], β-amino alcohols [3], and homoallylic amines [4][5], and can serve as building blocks for the preparation of

Polymerization of novel methacrylated anthraquinone dyes

• Christian Dollendorf,
• Susanne Katharina Kreth,
• Soo Whan Choi and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 453–459, doi:10.3762/bjoc.9.48

• materials used for iris implants or other medical applications. Conclusion In conclusion, a series of novel anthraquinone based polymerizable dyes has been synthesized by nucleophilic aromatic substitution reactions of anthraquinone derivatives with several amino alcohols. Depending on the moieties that

Enantioselective total synthesis of (R)-(−)-complanine

• Krystal A. D. Kamanos and
• Jonathan M. Withey

Beilstein J. Org. Chem. 2012, 8, 1695–1699, doi:10.3762/bjoc.8.192

• with a γ-aminobutyric acid (GABA) derivative. Complanine is structurally related to the obscuraminols, isolated from another marine source, the ascidian Pseudodistoma obscurum [2]. Unlike complanine, however, these substances are simple amino alcohols that do not possess any other chemical

• was synthesized in a sequence of nine linear steps, beginning with (R)-malic acid [3]. As part of our research endeavours directed towards the organocatalytic synthesis of 1,2-amino alcohols, we have developed a new asymmetric strategy leading to (R)-(−)-complanine. This approach utilizes an

Exploring chemical diversity via a modular reaction pairing strategy

• Joanna K. Loh,
• Sun Young Yoon,
• Thiwanka B. Samarakoon,
• Alan Rolfe,
• Patrick Porubsky,
• Benjamin Neuenswander,
• Gerald H. Lushington and
• Paul R. Hanson

Beilstein J. Org. Chem. 2012, 8, 1293–1302, doi:10.3762/bjoc.8.147

• the diversification of these core scaffolds with a variety of chiral, non-racemic amines/amino alcohols, by intermolecular SNAr utilizing benzoxathiazocine 1,1-dioxide 4 as the test substrate (Table 1). A variety of reaction conditions (equiv of amine, presence of base, concentration of solvent, time

Asymmetric organocatalytic decarboxylative Mannich reaction using β-keto acids: A new protocol for the synthesis of chiral β-amino ketones

• Chunhui Jiang,
• Fangrui Zhong and
• Yixin Lu

Beilstein J. Org. Chem. 2012, 8, 1279–1283, doi:10.3762/bjoc.8.144

• ketones are an important class of building blocks for the synthesis of 1,3-amino alcohols [1][2], 1,3-amino acids [3] and other bioactive nature products [4][5][6]. Given their synthetic significance, methods for the asymmetric synthesis of β-amino ketones have been extensively investigated over the past

Synthesis of a library of tricyclic azepinoisoindolinones

• Bettina Miller,
• Shuli Mao,
• Kara M. George Rosenker,
• Joshua G. Pierce and
• Peter Wipf

Beilstein J. Org. Chem. 2012, 8, 1091–1097, doi:10.3762/bjoc.8.120

• ]. Yields and purities of amino alcohols 9{1–12} and 10{1–13} are summarized in Table 1. The 9{1–11}/10{1–11} isolated product ratios varied between 5:1 and 1.5:1, with no obvious trends discernable. Interestingly, for adamantyl amine 8{13}, only the corresponding 10{13} was isolated, most likely due to the

• ]. Conclusion A library of novel tricyclic isoindolinone amino alcohols was prepared in seven steps from commercially available starting materials. Key transformations include the addition of in situ generated alkenylalanes to an N-acyliminium ion derived from pivaloate 1, a tandem ring-closing metathesis

• 2 in the absence of Ti(OiPr)4 and isolation of hydroxy epoxide 6 after treatment with m-CPBA. Preparation and RCM reaction of bis-terminal diene analogue 7. Conversion of epoxide 5 to 1,2-amino alcohols. Library matrix of products 9{1–13} and 10{1–13} [isolated yield (%) and purity by ELSD

Carbohydrate-auxiliary assisted preparation of enantiopure 1,2-oxazine derivatives and aminopolyols

• Marcin Jasiński,
• Dieter Lentz and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2012, 8, 662–674, doi:10.3762/bjoc.8.74

• [58], and pyran derivatives [59]. Gratifyingly, the treatment of tetrahydro-2H-1,2-oxazine derivatives 12 and 13 with an excess of SmI2 in tetrahydrofuran smoothly provided the expected amino alcohols 16 and 17 in excellent yields (Scheme 5). In order to compare the behaviour of a compound still

• bearing the N-auxiliary, we converted tetrahydro-2H-1,2-oxazine 7 into the O-benzylated derivative 18 under standard conditions (Scheme 6). Treatment of this protected compound with samarium diiodide furnished a complex mixture of products from which only the two amino alcohols 19 and 20 were isolated, in

Enantioselective supramolecular devices in the gas phase. Resorcin[4]arene as a model system

• Caterina Fraschetti,
• Matthias C. Letzel,
• Antonello Filippi,
• Maurizio Speranza and
• Jochen Mattay

Beilstein J. Org. Chem. 2012, 8, 539–550, doi:10.3762/bjoc.8.62

• . Cyclochiral resorcin[4]arenes. Studied (a) peptidoresorcin[4]arenes and (b) dipeptidic guests. Exchange rate constants (k × 10−11 cm3 molecule−1 s−1). Exchange rate constants (k × 10−10 cm3 molecule−1 s−1). Rate constant ratios (Equation 6). Overview of investigated amino acids, amino alcohols and amino acid

Synthesis of highly functionalized β-aminocyclopentanecarboxylate stereoisomers by reductive ring opening reaction of isoxazolines

• Melinda Nonn,
• Loránd Kiss,
• Reijo Sillanpää and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2012, 8, 100–106, doi:10.3762/bjoc.8.10

• , University of Szeged, Eötvös u. 6, H-6720 Szeged, Hungary 10.3762/bjoc.8.10 Abstract A rapid and simple procedure was devised for the synthesis of multifunctionalized cyclic β-amino esters and γ-amino alcohols via the 1,3-dipolar cycloaddition of nitrile oxides to β-aminocyclopentenecarboxylates. The

• molecules such as β-hydroxyketones [7][8][9][10], amino alcohols or amino acids [11][12][13][14][15][16][17], etc. The multifunctionalized cyclic amino acids – e.g., the antibiotic Oryzoxymycin [18][19][20][21], the antiviral agents Tamiflu [22][23][24][25][26][27][28][29][30][31][32][33], Zanamivir and 2,3

• . When the reduction was carried out with NaBH4 in EtOH, three products were obtained: The epimerized isoxazoline-fused amino carboxylate 7 and amino alcohols 8 and 9 which were separated by chromatography and isolated (Scheme 2). Thus, this reaction did not lead to the formation of highly functionalized

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