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John P. Schaefer

Bio: John P. Schaefer is an academic researcher from University of Arizona. The author has contributed to research in topics: Triphenylphosphine & Solvolysis. The author has an hindex of 11, co-authored 27 publications receiving 307 citations.


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749 citations

Journal ArticleDOI
TL;DR: Most organic polymeric materials melt below 200 °C and most of them begin to degrade rapidly at temperatures only slightly above 200°G. Thermally stable polymers are those which will withstand much higher temperatures without loss of strength or change of structure as mentioned in this paper.
Abstract: Most organic polymeric materials melt below 200 °C and most of them begin to degrade rapidly at temperatures only slightly above 200°G. Thermally stable polymers are generally considered to be those which will withstand much higher temperatures without loss of strength or change of structure. In general we expect these materials to withstand at least 300°C in air and up to 500°C or higher in inert atmospheres. Polymers which show these properties are usually highly aromatic in structure, often with heterocyclic units, high melting, sometimes infusible and usually with low solubility in all solvents. This makes their fabrication very difficult and as a consequence limits their usefulness.

587 citations

Journal ArticleDOI
TL;DR: Structures of anisomycin, chloramphenicol, sparsomycin), blasticidin S, and virginiamycin M bound to the large ribosomal subunit of Haloarcula marismortui have been determined at 3.0A resolution, consistent with their functioning as competitive inhibitors of peptide bond formation.

386 citations

Journal ArticleDOI
TL;DR: The purpose of this review is to give the reader a tour of the methods that have emerged in the last few years so one can appreciate the myriad of different metals and reagents that can accomplish the oxyamination of alkenes.
Abstract: 1,2-Amino alcohols are high-value, versatile functional groups that are found in scores of biologically active molecules and other interesting synthetic targets such as ligands and auxiliaries. Given their prominent position within organic compounds of import, it is no surprise to note that many routes have been developed to access this motif and there are many different starting points from which a synthetic chemist might embark on a synthesis. However, one particular approach stands out from the others, and this is the direct conversion of an alkene to a vicinal amino alcohol derivative (oxyamination). Research in this field has been particularly active in recent years and many interesting new methodologies have been reported. The purpose of this review is to give the reader a tour of the methods that have emerged in the last few years so one can appreciate the myriad of different metals and reagents that can accomplish the oxyamination of alkenes. There are still many challenges to be overcome and, herein, we also outline the areas that are ripe for further development and which bode well for the future.

219 citations