Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• ] were converted to the corresponding triscatecholates 11 and 13 by coupling to dopamine (Scheme 2). The resulting triscatecholates 11 and 13 may be used as synthetically flexible platforms for functionalizations of surfaces via either nucleophilic addition (to the Michael acceptor in 11) or radical

• chemistry after immobilization. Immobilization on ZnO NPs Three different catecholates were selected to study the binding properties to ZnO NPs (Figure 2). Monomeric PEG-catecholate 14 [46] and the tripodal homologue 3 were chosen to study the stability of the coatings and the particles in aqueous solution

Visible-light photoredox catalysis enabled bromination of phenols and alkenes

• Yating Zhao,
• Zhe Li,
• Chao Yang,
• Run Lin and
• Wujiong Xia

Beilstein J. Org. Chem. 2014, 10, 622–627, doi:10.3762/bjoc.10.53

• regioselectivity for the bromination of phenols and alkenes. Further development of photoredox catalysis in the context of radical chemistry and its application in other reactions are currently underway in our laboratory. Experimental General procedure for the bromination of phenols and alkenes To a 10 mL round

The renaissance of organic radical chemistry – deja vu all over again

• Corey R. J. Stephenson,
• Armido Studer and
• Dennis P. Curran

Beilstein J. Org. Chem. 2013, 9, 2778–2780, doi:10.3762/bjoc.9.312

• organic radical chemistry dates back over 110 years, and it has been thriving for decades because it continuously reinvents itself. Often this happens when groups of researchers with different interests and expertise immigrate to the field. About 30 years ago there began a flourishing period in the field

• of organic radical chemistry that delivered groundbreaking results, especially in organic synthesis. By the 1990’s, radical reactions (especially cyclizations) were broadly recognized as powerful tools to make molecules. This Renaissance I in organic radical chemistry was built on prior renaissances

• radical chemistry addressing all these major fields can be found in the recently published four-volume “Encyclopedia of Radicals in Chemistry, Biology and Materials” [2]. Over the past few years, the process has again come full circle as research in organic radical chemistry, especially synthetic radical

Damage of polyesters by the atmospheric free radical oxidant NO₃^•: a product study involving model systems

• Catrin Goeschen and
• Uta Wille

Beilstein J. Org. Chem. 2013, 9, 1907–1916, doi:10.3762/bjoc.9.225

• Catrin Goeschen Uta Wille ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Chemistry and Bio21 Institute, The University of Melbourne, 30 Flemington Road, Parkville, VIC 3010, Australia 10.3762/bjoc.9.225 Abstract Manufactured polymer materials are used in

Creating Complexity

• Donald Craig

Beilstein J. Org. Chem. 2013, 9, 1881–1882, doi:10.3762/bjoc.9.220

• of catalysis, radical chemistry, stereoselective synthesis and molecular diversity. I thank them warmly for their high-quality contributions, which demonstrate the central role of organic synthesis in all its guises, in the creation of complexity. Donald Craig London, July 2013

Aerobic radical multifunctionalization of alkenes using tert-butyl nitrite and water

• Daisuke Hirose and
• Tsuyoshi Taniguchi

Beilstein J. Org. Chem. 2013, 9, 1713–1717, doi:10.3762/bjoc.9.196

• the current work has shown that this old methodology still has a large potential. The development of other direct C–H functionalization reactions based on radical chemistry is currently on-going together with further optimization of the presented reaction in our laboratory. The effect of water in

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• reactions of aryl halides with H–P compounds [5][6][7] and catalytic addition to nonpolar unsaturated carbon–carbon bonds [8][9][10][11]. In the field of radical chemistry, the addition of phosphorus radicals, mainly from H–P compounds, onto carbon–carbon multiple bonds [12][13][14][15] has held a special

The synthesis of well-defined poly(vinylbenzyl chloride)-grafted nanoparticles via RAFT polymerization

• John Moraes,
• Kohji Ohno,
• Guillaume Gody,
• Thomas Maschmeyer and
• Sébastien Perrier

Beilstein J. Org. Chem. 2013, 9, 1226–1234, doi:10.3762/bjoc.9.139

• , and we demonstrate that the exceptional control over their dimensions is achieved by careful tailoring the conditions of the radical polymerization. Keywords: core–shell particles; free radical; grafting; RAFT polymerization; silica; Introduction The versatility of organic free radical chemistry in

Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

• Hideto Miyabe,
• Ryuta Asada and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2013, 9, 1148–1155, doi:10.3762/bjoc.9.128

• ][30][31][32][33][34][35][36]. We have also directed our efforts toward the development of new and efficient cascade approaches for the construction of carbon–carbon/heteroatom bonds based on radical chemistry. These approaches can be classified into two categories according to their reaction mechanism

• chiral Lewis acid and these substrates. Keywords: cascade; cyclization; enantioselective; free radical; Lewis acid; radical; Introduction Strategies involving a cascade process offer the advantage of multiple carbon–carbon and/or carbon–heteroatom bond formations in a single operation. Radical

• chemistry has been developed as one of the most powerful tools for carbon–carbon bond formation in organic synthesis [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Particularly, the advantages for utilizing the radical methodologies are the high functional group tolerance and the

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• is not possible for the Bu• radical formed by cleavage of the stannane (the potential of the Bu+/Bu• couple is approximated here by that of the ethyl cation/ethyl radical couple [47]). Photoinduced electron transfer as an access to radical chemistry. Mechanistic scheme. Spectroscopic properties of

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• mersicarpine (60), is another illustration [31]. The aromatisation process in this example was incomplete under the usual conditions and required further treatment with manganese dioxide. The possibility of associating the radical chemistry of xanthates with various ionic reactions represents another powerful

• tricyclic structure 93. In this sequence too, the chirality present in the starting material 89 is initially derived from an allylic alcohol by the Claisen rearrangement and is then transmitted to the other centres. Another powerful reaction that can be associated with the radical chemistry of xanthates is

• degenerative radical addition–transfer of xanthates is by far the most powerful radical chemistry that we have been able to discover, for it allows efficient intermolecular carbon–carbon bond formation starting with unactivated alkenes under very mild experimental conditions. Various functional groups can

Evaluation of a chiral cubane-based Schiff base ligand in asymmetric catalysis reactions

• Kyle F. Biegasiewicz,
• Michelle L. Ingalsbe,
• Jeffrey D. St. Denis,
• James L. Gleason,
• Junming Ho,
• Michelle L. Coote,
• G. Paul Savage and
• Ronny Priefer

Beilstein J. Org. Chem. 2012, 8, 1814–1818, doi:10.3762/bjoc.8.207

• ARC Centre of Excellence for Free-Radical Chemistry and Biotechnology, Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia CSIRO Materials Science and Engineering, Clayton South MDC 3169, Australia College of Pharmacy, Western New England University, Springfield

Physical organic chemistry

• John A. Murphy

Beilstein J. Org. Chem. 2010, 6, 1025–1025, doi:10.3762/bjoc.6.116

• to me, the transformation of radical chemistry from being an almost impenetrable area to one that can be usefully harnessed even in synthetic applications, has been extraordinary – this transformation has been relatively recent and has been principally dependent on the accurate determination of

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• ], sigmatropic rearrangements [21] and as either thiyl radical precursors [22] or as a source of hydrogen in radical chemistry [23]. With the appropriate sulfur derivative, stereoselective variants of all these transformations can be envisaged. Currently, there are few examples of sulfur containing [2.2

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• provide an efficient termination of radical processes, and the low yields of isolated compounds could be consistent with radical chemistry where efficient termination was lacking. With this as guidance to our thinking, the remaining substrates below were designed to provide internal termination routes for

• the radical chemistry. One way to achieve clean termination of the radical process would be by providing a radical leaving group adjacent to the cyclised radical 19. Appropriate groups might be sulfide, sulfoxide and sulfonyl groups [64][65]. Accordingly, arenediazonium salts 31a–d were prepared

Part 2. Mechanistic aspects of the reduction of S-alkyl- thionocarbonates in the presence of triethylborane and air

• Florent Allais,
• Jean Boivin and
• Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 46, doi:10.1186/1860-5397-3-46

• role of water or alcohols and solvents in the reduction of S-alkylxanthates and related compounds. Hydrogen transfer from the O-H bond present in water or in an alcohol is not an obvious hypothesis in radical chemistry because of the high BDE of the O-H bond. Our results corroborate Wood's findings