Author(s): Mattia Silvi ; Paolo Melchiorre (corresponding author) [2, 3] The preparation of chiral molecules with a well-defined, three-dimensional spatial arrangement is central to synthetic chemistry. Enantioselective organocatalysis offers powerful [...] Organocatalysiscatalysis mediated by small chiral organic moleculesis a powerful technology for enantioselective synthesis, and has extensive applications in traditional ionic, two-electron-pair reactivity domains. Recently, organocatalysis has been successfully combined with photochemical reactivity to unlock previously inaccessible reaction pathways, thereby creating new synthetic opportunities. Here we describe the historical context, scientific reasoning and landmark discoveries that were essential in expanding the functions of organocatalysis to include one-electron-mediated chemistry and excited-state reactivity.
Carbon -- Research, Chemistry, Organic -- Research, Substrates (Biochemistry) -- Research, and Chemical research
Author(s): Rohan E. J. Beckwith The basis of organic chemistry is the study of carbon-containing compounds with the aim of manipulating carbon atoms to generate new molecules through the formation [...]
Murphy, John J., Bastida, David, Paria, Suva, Fagnoni, Maurizio, and Melchiorre, Paolo
Nature. April 14, 2016, Vol. 532 Issue 7598, p218, 5 p.
Radicals (Chemistry) -- Analysis, Chemistry, Organic -- Analysis, and Carbon -- Chemical properties
An important goal of modern organic chemistry is to develop new catalytic strategies for enantioselective carbon-carbon bond formation that can be used to generate quaternary stereogenic centres. Whereas considerable advances [...]
Cocinero, Emilio J., Carcabal, Pierre, Vaden, Timothy D., Simons, John P., and Davis, Benjamin G.
Nature. Jan 6, 2011, Vol. 469 Issue 7328, p76, 5 p.
Peptides -- Chemical properties, Peptides -- Spectra, Heterocyclic compounds -- Chemical properties, Chemistry, Organic -- Research, and Carbohydrates -- Chemical properties
The preferential stabilization (10) of pyranose sugar rings when they contain an axial electronegative substituent at C1 (Fig. 1a) is contrary to expectations based on considerations of steric or solvation [...] The anomeric effect is a chemical phenomenon (1-9) that refers to an observed stabilization (10) of six-membered carbohydrate rings when they contain an electronegative substituent at the C1 position of the ring. This stereoelectronic effect influences the three-dimensional shapes of many biological molecules. It can be manifested not only in this classical manner involving interaction of the endocyclic oxygen atom (O5) found in such sugars with the C1 substituent (endo-anomeric effect) but also through a corresponding interaction of the electronegative exocyclic substituent with O5 (exo-anomeric effect). However, the underlying physical origin(s) of this phenomenon is still not clear (1,3,4,11-14). Here we show, using a combination of laser spectroscopy and computational analysis, that a truncated peptide motif can engage the two anomers of an isolated sugar in the gas phase, an environment lacking extraneous factors which could confound the analysis. (Anomers are isomers that differ in the orientation of the substituent at C1.) Complexes formed between the peptide and the [alpha]- or [beta]-anomers of D-galactose are nearly identical structurally; however, the strength of the polarization of their interactions with the peptide differs greatly. Natural bond order calculations support this observation, and together they reveal the dominance of the exo- over the endo-anomeric effect. As interactions between oxygen atoms at positions C1 and C2 (O1 and O2, respectively) on the pyranose ring can alter the exo/endo ratio of a carbohydrate, our results suggest that it will be important to reevaluate the influence, and biological effects, of substituents at position C2 in sugars.
Nature. Dec 18, 2014, Vol. 516 Issue 7531, p332, 2 p.
Radicals (Chemistry) -- Properties, Olefins -- Chemical properties, and Chemistry, Organic
Author(s): Steven L. Castle (corresponding author)  Reactions that form carbon-carbon (C-C) bonds are essential for synthesizing complex organic molecules from simple, inexpensive precursors. The value that such molecules have [...]
Nature. June 26, 2014, Vol. 510 Issue 7506, p447, 1 p.
Microbial enzymes -- Research, Chemical synthesis -- Analysis, and Chemistry, Organic -- Analysis
The metabolism of living organisms could be harnessed to help construct small molecules, according to a team from Harvard University in Cambridge, Massachusetts. Chemists routinely use microbial enzymes as catalysts. [...]
Chemical synthesis -- Research, Chemistry, Organic -- Research, and Second messengers (Biochemistry) -- Research
Chemical messengers called prostaglandins are present in nearly all mammalian tissues. These elusive molecules mediate an extraordinary number of biological processes--including the regulation of body temperature, the contraction and relaxation [...]