Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• , the cis isomer brings the aromatic rings closer, shortening its length, and hence the channel blocking is inefficient, allowing the passage of ions. The development of systems capable of photoregulating the activity of ion channels is extremely important in neurobiology. Recently, a maleimide

• , azobenzene and glutamate derivative (MAG) was used as a photochromic agonist of an ionotropic glutamate receptor (iGluR) (Figure 5a) [89][90][91]. The chromophore consists of a terminal maleimide unit, which is associated covalently to the protein via a cysteine residue, a central azobenzene unit and a

Formation of carbohydrate-functionalised polystyrene and glass slides and their analysis by MALDI-TOF MS

• Martin J. Weissenborn,
• Johannes W. Wehner,
• Christopher J. Gray,
• Robert Šardzík,
• Claire E. Eyers,
• Thisbe K. Lindhorst and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2012, 8, 753–762, doi:10.3762/bjoc.8.86

• generally compatible with other platforms in our laboratories, such as through the formation of SAMs on gold [18] or by coupling into maleimide-functionalised surfaces in a chemoselective fashion [19]. For the initial studies two carbohydrate derivatives, 5 and 7, were synthesised. The α-D-mannoside 5 would

A concise synthesis of 3-(1-alkenyl)isoindolin-1-ones and 5-(1-alkenyl)pyrrol-2-ones by the intermolecular coupling reactions of N-acyliminium ions with unactivated olefins

• Nianhong Lu,
• Lihong Wang,
• Zhanshan Li and
• Wei Zhang

Beilstein J. Org. Chem. 2012, 8, 192–200, doi:10.3762/bjoc.8.21

• reduction of the parent phthalimide [35] and maleimide [36] derivatives. In order to explore the effects of the experimental conditions on the coupling reactions, the reaction of 1a with styrene (2a) was selected as a representative and carried out at room temperature under different conditions (Table 1

Synthesis of rigidified flavin–guanidinium ion conjugates and investigation of their photocatalytic properties

• Harald Schmaderer,
• Mouchumi Bhuyan and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 26, doi:10.3762/bjoc.5.26

• for the cycloaddition of maleimide to anthracene in toluene (Scheme 5). Table 3 summarizes the results. A significantly higher yield of the cycloaddition product was obtained after 8 h at 40 °C in the presence of compound 2 (entry 3), if compared to the control reaction (entry 6). Upon irradiation

• reaction (entry 4). Blue light irradiated flavins accelerate the anthracene maleimide cycloaddition significantly, but flavins 1 and 2 do not provide additional benefit if compared to tetraacetyl flavin 3. Conclusion We have prepared new flavin derivatives that bear an acyl guanidinium group, which is

C₂-symmetric bisamidines: Chiral Brønsted bases catalysing the Diels- Alder reaction of anthrones

• Deniz Akalay,
• Gerd Dürner,
• Jan W. Bats and
• Michael W. Göbel

Beilstein J. Org. Chem. 2008, 4, No. 28, doi:10.3762/bjoc.4.28

• compounds 2 could be introduced by a Mitsunobu alkylation of maleimide [12]. Alternatively, substituted maleimides were prepared by reaction of maleic anhydride with the corresponding amines followed by ring closure [13][14]. Cycloaddition kinetics of 1a and 2a was examined first by 1H NMR in CD2Cl2 at room

• yields and with moderate values of ee. A remarkable increase in enantioselectivity was observed using maleimide 2i. The steric hindrance imposed by the large 2,6-diisopropylphenyl moiety of 2i resulted in 76% ee at −70 °C but also lowered reaction rates. Only 13% yield could be obtained under such