Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time ¹³C CP-MAS solid-state NMR characterization

• Isabelle Mallard,
• Davy Baudelet,
• Franca Castiglione,
• Monica Ferro,
• Walter Panzeri,
• Enzio Ragg and
• Andrea Mele

Beilstein J. Org. Chem. 2015, 11, 2785–2794, doi:10.3762/bjoc.11.299

• of the two experimental spectra reveals that no chemical shift variations are observed. Consequently, no relevant structural modification occurs on the β-CD moiety during the polymerization process. Dynamics of cross polarization – theoretical description Important features of the dynamic behavior of

Mechanism, kinetics and selectivity of selenocyclization of 5-alkenylhydantoins: an experimental and computational study

• Biljana M. Šmit,
• Radoslav Z. Pavlović,
• Dejan A. Milenković and
• Zoran S. Marković

Beilstein J. Org. Chem. 2015, 11, 1865–1875, doi:10.3762/bjoc.11.200

• do not arise from the hydantoin nucleus itself but from different substituents that have been attached to it. During the last decades, the effect of the structural modification on the biological activity of the hydantoin derivatives has been studied intensively [12]. Due to their various biological

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• investigations have shown that beside their antibacterial activity, some macrolides exhibit anti-inflammatory/immunomodulatory [5][6][7][8][9][10], antitumor [11][12][13], antiviral [10] or antimalarial [14][15] activity. These discoveries have sparked a new interest in the structural modification of macrolides

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• out of 60 original works cited in this review appeared within the last five years. Up to date, much more efforts were devoted to the preparation of novel nucleoside scaffolds by a structural modification of the parent nucleosides (37 examples) than by their de novo construction from non-nucleoside

Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction

• Marina Rubina,
• William M. Sherrill,
• Alexey Yu. Barkov and
• Michael Rubin

Beilstein J. Org. Chem. 2014, 10, 1536–1548, doi:10.3762/bjoc.10.158

• selectivity. Structural modification of the flat ortho-phenylene tether in the Pfaltz ligand through the incorporation of additional chirality elements into the ligand backbone allowed for significant improvement of the enantioselectivity. Thus, ferrocene-based ligands introduced by Dai and Hou [55][56], and

Cyclization of substitued 2-(2-fluorophenylazo)azines to azino[1,2-c]benzo[d][1,2,4]triazinium derivatives

• Aleksandra Jankowiak,
• Emilia Obijalska and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2013, 9, 1873–1880, doi:10.3762/bjoc.9.219

• Table 1. For further probing of the cyclization mechanism, the mildly activating [13][14] N=N-bridging group in 4c–Z was replaced by the non-activating CH=CH group in 13-Z (Figure 6). A computational analysis demonstrated that this structural modification resulted in a modest increase of activation

Development of peptidomimetic ligands of Pro-Leu-Gly-NH₂ as allosteric modulators of the dopamine D₂ receptor

• Swapna Bhagwanth,
• Ram K. Mishra and
• Rodney L. Johnson

Beilstein J. Org. Chem. 2013, 9, 204–214, doi:10.3762/bjoc.9.24

• to date are exogenous synthetic molecules that have been identified through screening protocols and then subsequently optimized through structural modification [2]. Although PLG’s pharmacological profile suggested that this compound would have potential in treating neurological diseases such as

Synthesis and characterization of Sant-75 derivatives as Hedgehog-pathway inhibitors

• Chao Che,
• Song Li,
• Bo Yang,
• Shengchang Xin,
• Zhixiong Yu,
• Taofeng Shao,
• Chuanye Tao,
• Shuo Lin and
• Zhen Yang

Beilstein J. Org. Chem. 2012, 8, 841–849, doi:10.3762/bjoc.8.94

• . Subsequently, Infinity Pharmaceuticals developed cyclopamine-based Smo inhibitors IPI-926 through structural modification on the A and D rings. IPI-926 exhibited improved pharmaceutical properties as well as a favorable pharmacokinetic profile, and showed complete tumor regression in a Hh-dependent

• ), all of which will help us to more distinctly study the SAR in motif A. Compounds 8a–h were either synthesized using reported methods [42][43][44][45][46] or are commercially available. Substituent-modifications on the motif B In the second series of novel scaffolds, structural modification was focused

Toward an integrated route to the vernonia allenes and related sesquiterpenoids

• Da Xu,
• Michael A. Drahl and
• Lawrence J. Williams

Beilstein J. Org. Chem. 2011, 7, 937–943, doi:10.3762/bjoc.7.104

• due to inadequate relative orientation [47][48]. For our purposes, we aimed to identify a scaffold that would readily adopt the ideal, or near-ideal, stereoelectronic arrangement necessary for C–C fragmentation, and yet, would have the potential to accept further structural modification without

• . Computational studies suggest that the diene scaffold may be suitable for further structural modification and adopt the stereoelectronic arrangement necessary for C–C fragmentation. Further studies will be reported in due course. Experimental Preparation of endocyclic allene 25: In a 25 mL flame-dried flask

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 synthesis of naturally occurring iminocyclitols and in their structural modification. Consequently, efficient and stereoselective synthetic routes have been developed, often starting from an inexpensive chiral-pool of precursors, in particular carbohydrates that share structural features with

Ring-alkyl connecting group effect on mesogenic properties of p-carborane derivatives and their hydrocarbon analogues

• Aleksandra Jankowiak,
• Piotr Kaszynski,
• William R. Tilford,
• Kiminori Ohta,
• Adam Januszko,
• Takashi Nagamine and
• Yasuyuki Endo

Beilstein J. Org. Chem. 2009, 5, No. 83, doi:10.3762/bjoc.5.83

• dramatic effect has been attributed to conformational properties of molecules in the condensed phase. A more complete understanding of the impact of structural modification on bulk properties will emerge through further research on structure-property relationships and studying of other examples of

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• , this structural modification would facilitate a final release of the β2-amino acid by hydrogenolysis of all remaining benzyl-type N-protective groups. Results and Discussion Cyclocondensation of benzaldehyde and β-amino acid amides to 2-phenyl-tetrahydropyrimidine-4(1H)-ones is problematic, since

New acylides: synthesis of 3-O-[γ-(4-oxo-2-aryl- thiazolidin- 3-yl)butyryl]erythromycin A derivatives

• Deepa Pandey,
• Wahajul Haq and
• Seturam B. Katti

Beilstein J. Org. Chem. 2008, 4, No. 14, doi:10.3762/bjoc.4.14

• acylide (3-O-acyl derivatives of decladinosyl-6-O-methylerythromycin) derivatives [8][9] (Figure 2). However structural modification and generation of new prototypes has been challenging due to structural complexity of the erythromycin molecule. Therefore, development of new strategies for the synthesis