Angewandte Chemie

Angewandte Chemie

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Weinheim, Germany / Angewandte Chemie, A Journal of the German Chemical Society (GDCh) - the leading journal in chemistry
Angewandte Chemie
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Angewandte celebrates its 125th anniversary. Read more in the Editorial by editor Peter Gölitz (http://doi.org/fz9w7j) and join the jubilee symposium in Berlin on March 12. It will also be broadcast live (and recorded) on Chemistryviews.org free of charge: http://bit.ly/XmZQj9

Angewandte celebrates its 125th anniversary. Read more in the Editorial by editor Peter Gölitz (http://doi.org/fz9w7j) and join the jubilee symposium in Berlin on March 12. It will also be broadcast live (and recorded) on Chemistryviews.org free of charge: http://bit.ly/XmZQj9

A blooming tree illustrates how CO2 can be recycled to a variety of chemicals based on a strategy discussed by T. Cantat and co-workers in their Communication on page 187 ff. The approach relies on the simultaneous use of a functionalizing reagent and a reductant that can be independently adjusted to access a variety of molecules from CO2. The direct conversion of CO2, amines, and silanes to formamides is reported. http://doi.org/c5fr77

A blooming tree illustrates how CO2 can be recycled to a variety of chemicals based on a strategy discussed by T. Cantat and co-workers in their Communication on page 187 ff. The approach relies on the simultaneous use of a functionalizing reagent and a reductant that can be independently adjusted to access a variety of molecules from CO2. The direct conversion of CO2, amines, and silanes to formamides is reported. http://doi.org/c5fr77

UV light provides the energy required for directional transport of a small-molecule walker along a molecular track. In their Communication on page 285 ff., D. Leigh and co-workers describe how different sequences of stimuli can induce an 18-atom two-legged molecular unit to “walk” predominantly towards one or the other end of a track with four footholds. http://doi.org/cjkcdk

UV light provides the energy required for directional transport of a small-molecule walker along a molecular track. In their Communication on page 285 ff., D. Leigh and co-workers describe how different sequences of stimuli can induce an 18-atom two-legged molecular unit to “walk” predominantly towards one or the other end of a track with four footholds. http://doi.org/cjkcdk

The composition of Stradivari's varnish has raised numerous hypotheses and controversies for the past two centuries. In their Communication, J.-P. Echard, L. Bertrand et al. describe the chemical stratigraphy of the varnishes from five representative Stradivari instruments by using a wide array of analytical techniques. In particular, Stradivari used several red pigments, and may have sought a variety of tints to give his instruments their beautiful appearance. http://doi.org/c5fn53

The composition of Stradivari's varnish has raised numerous hypotheses and controversies for the past two centuries. In their Communication, J.-P. Echard, L. Bertrand et al. describe the chemical stratigraphy of the varnishes from five representative Stradivari instruments by using a wide array of analytical techniques. In particular, Stradivari used several red pigments, and may have sought a variety of tints to give his instruments their beautiful appearance. http://doi.org/c5fn53

The last decade witnessed the successful synthesis of metal nanocrystals in a rich variety of shapes. A typical synthesis can be divided into three distinct stages: nucleation, evolution of nuclei into seeds, and growth of seeds into nanocrystals. As illustrated in the cover picture and discussed by Y. Xia et al. in their Review, the final shape of a nanocrystal is determined primarily by the internal structure of the seed and the binding of the capping agent. http://doi.org/c5fk8w

The last decade witnessed the successful synthesis of metal nanocrystals in a rich variety of shapes. A typical synthesis can be divided into three distinct stages: nucleation, evolution of nuclei into seeds, and growth of seeds into nanocrystals. As illustrated in the cover picture and discussed by Y. Xia et al. in their Review, the final shape of a nanocrystal is determined primarily by the internal structure of the seed and the binding of the capping agent. http://doi.org/c5fk8w

By the biochemical technique of rolling-circle amplification (RCA), a circular oligonucleotide sequence serves as a template for the synthesis of a complementary single-stranded DNA chain. If the DNA chain contains aptamers for a protein such as thrombin or lysozyme, subsequent complexation results in periodic protein–DNA composites. I. Willner et al. describe such compounds and even assemblies of DNA, protein, and gold nanoparticles: http://doi.org/bw32sj

By the biochemical technique of rolling-circle amplification (RCA), a circular oligonucleotide sequence serves as a template for the synthesis of a complementary single-stranded DNA chain. If the DNA chain contains aptamers for a protein such as thrombin or lysozyme, subsequent complexation results in periodic protein–DNA composites. I. Willner et al. describe such compounds and even assemblies of DNA, protein, and gold nanoparticles: http://doi.org/bw32sj

J. de Mendoza and co-workers describe in their Communication on page 198 ff. how a host molecule (a small calix[4]arene or cavitand) can itself become the “prey” for a larger host (a metallocavitand made from a calix[4]arene with [3,8]phenanthroline subunits linked through Re atoms). The cover picture shows the complexation of a cavitand (by P. Ballester) superimposed on an underwater picture at Cap Andritxol, Mallorca (by E. Botana). http://doi.org/btzkd9

J. de Mendoza and co-workers describe in their Communication on page 198 ff. how a host molecule (a small calix[4]arene or cavitand) can itself become the “prey” for a larger host (a metallocavitand made from a calix[4]arene with [3,8]phenanthroline subunits linked through Re atoms). The cover picture shows the complexation of a cavitand (by P. Ballester) superimposed on an underwater picture at Cap Andritxol, Mallorca (by E. Botana). http://doi.org/btzkd9

Retro-cycloaddition of easily prepared pyrrolidinofullerenes affords quantitatively pristine fullerenes, and thus can be used as a new protection-deprotection protocol in the chemistry of fullerenes, as shown in the cover picture. In their Communication on page 110 ff., N. Martín, L. Echegoyen, and co-workers report on this promising finding, which has already allowed the selective isolation of the Ih constitutional isomer of Sc3N@C80. http://doi.org/bxx2nc

Retro-cycloaddition of easily prepared pyrrolidinofullerenes affords quantitatively pristine fullerenes, and thus can be used as a new protection-deprotection protocol in the chemistry of fullerenes, as shown in the cover picture. In their Communication on page 110 ff., N. Martín, L. Echegoyen, and co-workers report on this promising finding, which has already allowed the selective isolation of the Ih constitutional isomer of Sc3N@C80. http://doi.org/bxx2nc

Unnatural amino acids can be incorporated as new building blocks into genetic codes  to facilitate studies of protein structure and function. Over 30 unnatural amino acids with modified side chains have been genetically encoded in response to unique triplet and quadruplet codons. L. Wang and P. G. Schultz describe in their Review chemical and biochemical approaches that have been developed to manipulate protein structure and add new amino acids to the genetic code. http://doi.org/cj72qs

Unnatural amino acids can be incorporated as new building blocks into genetic codes to facilitate studies of protein structure and function. Over 30 unnatural amino acids with modified side chains have been genetically encoded in response to unique triplet and quadruplet codons. L. Wang and P. G. Schultz describe in their Review chemical and biochemical approaches that have been developed to manipulate protein structure and add new amino acids to the genetic code. http://doi.org/cj72qs

Dip-Pen Nanolithography makes possible rapid patterning of surfaces on the nanometer scale. The cover picture clearly shows the principles of this technique: the deposition of dye molecules from an atomic force microscopy tip onto a substrate. Feymans 1960 dictum on miniturization, shown in nanometer-sized type in the background, is proving to be once again applicable. Review by C. A. Mirkin et al. http://doi.org/c5fcgt

Dip-Pen Nanolithography makes possible rapid patterning of surfaces on the nanometer scale. The cover picture clearly shows the principles of this technique: the deposition of dye molecules from an atomic force microscopy tip onto a substrate. Feymans 1960 dictum on miniturization, shown in nanometer-sized type in the background, is proving to be once again applicable. Review by C. A. Mirkin et al. http://doi.org/c5fcgt

The Art of Synthesis and the beauty of Nature lure so many chemists into total synthesis. The cover picture shows yellow jasmine, from which the poisonous alkaloid gelsemine was isolated. From these syntheses, we can learn which strategies represent the fastest and/or most efficient routes to the target. More about this fascinating compound and organic synthesis at its best can be found in the Review by S. J. Danishefsky and H. Lin on pg. 36 ff. http://doi.org/b879bf

The Art of Synthesis and the beauty of Nature lure so many chemists into total synthesis. The cover picture shows yellow jasmine, from which the poisonous alkaloid gelsemine was isolated. From these syntheses, we can learn which strategies represent the fastest and/or most efficient routes to the target. More about this fascinating compound and organic synthesis at its best can be found in the Review by S. J. Danishefsky and H. Lin on pg. 36 ff. http://doi.org/b879bf

The supramolecular cluster catalysis described lies at the interface of enzymatic (right flask), homogeneous (top flask), and heterogeneous catalysis (left flask). The central structure depicts a cluster capable of hydrogenating aromatic substrates under mild biphasic conditions. Most interestingly, the mechanism relies solely on hydrophobic interactions between the catalyst and the substrate. Süss-Fink et al. http://doi.org/cr695q

The supramolecular cluster catalysis described lies at the interface of enzymatic (right flask), homogeneous (top flask), and heterogeneous catalysis (left flask). The central structure depicts a cluster capable of hydrogenating aromatic substrates under mild biphasic conditions. Most interestingly, the mechanism relies solely on hydrophobic interactions between the catalyst and the substrate. Süss-Fink et al. http://doi.org/cr695q

... a model of the “progenitor-TADDOLs” in front of Swiss panorama. The model is flanked by a stylized view of the general mechanistic model for the preferred stereochemical pathway of the Ti–TADDOLate-catalyzed reaction of chelating substrates (left) and a blackboard (right) showing formulae of compounds that can be prepared with high enantioselectivity by nucleophilic addition in the presence of titanium TADDOLates. D. Seebach et al. http://doi.org/c34cxz

... a model of the “progenitor-TADDOLs” in front of Swiss panorama. The model is flanked by a stylized view of the general mechanistic model for the preferred stereochemical pathway of the Ti–TADDOLate-catalyzed reaction of chelating substrates (left) and a blackboard (right) showing formulae of compounds that can be prepared with high enantioselectivity by nucleophilic addition in the presence of titanium TADDOLates. D. Seebach et al. http://doi.org/c34cxz

Angewandte Chemie 1/2000 http://doi.org/bxjnf4

Angewandte Chemie 1/2000 http://doi.org/bxjnf4

From biological to chemical diversity: Nature produces molecules with a wide number of complex biological functions by synthesizing large, diverse collections of chemical structures and screening or selecting for a desired function. Today this same combinatorial approach is being used to synthesize large libraries of small organic compounds, natural products, peptides, proteins, nucleic acids, and even inorganic materials. Overview by David R. Liu and Peter G. Schultz http://doi.org/fw2hmk

From biological to chemical diversity: Nature produces molecules with a wide number of complex biological functions by synthesizing large, diverse collections of chemical structures and screening or selecting for a desired function. Today this same combinatorial approach is being used to synthesize large libraries of small organic compounds, natural products, peptides, proteins, nucleic acids, and even inorganic materials. Overview by David R. Liu and Peter G. Schultz http://doi.org/fw2hmk