the presence of a threonine-derived bioxazole core and an N-(1,1-dimethyl)allyl ("reverse prenyl") valine residue. In the context of our synthesis, efficient new strategies for the preparation of these segments were developed. The synthesis of two epimers of muscoride A allowed the unambiguous assignment of the relative and absolute configuration of the natural product by NMR and optical rotation analyses
propionaldehyde with 4-nitrobenzaldehyde, when combined with Lewis acids such as zinc triflate. A new class of hybrid Lewis acid/Lewisbase catalysts has been designed and prepared with an initial objective of promoting stereoselective direct aldol reactions. Several scaffolds were synthesized that contain amine moieties capable of enamine catalysis, connected to heterocyclic metal-chelating sections composed
Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation
作者:Dennis Wiedenhoeft、Adam R. Benoit、Yibiao Wu、Jacob D. Porter、Elisia Meyle、Teresa H.W. Yeung、Raechel Huff、Sergey V. Lindeman、Chris Dockendorff
DOI:10.1016/j.tet.2016.05.014
日期:2016.7
classes of hybridcatalysts have been synthesized by tethering heterocyclic metal (Lewis acid) chelating scaffolds to several different amines capable of facilitating enamine catalysis. Oxazole, thiazole, and imidazole-based chiral precatalysts were prepared in several steps from amino acid starting materials, and these were combined with a variety of metal Lewis acids for potential use as catalysts for various
DFT-assisted design and evaluation of bifunctional copper(I) catalysts for the direct intermolecular addition of aldehydes and ketones to alkynes
作者:Jacob D. Porter、Eric Greve、Abdulmohsen Alsafran、Adam R. Benoit、Sergey V. Lindeman、Chris Dockendorff
DOI:10.1016/j.tet.2018.07.034
日期:2018.9
structures of the designed catalysts were computed using density functional theory (DFT), and the relative energies of putative catalytic intermediates were estimated and used to prioritize catalyst designs. Novel bifunctional precatalysts containing a thiazole spacer were synthesized via a 9-step sequence and combined with transition metals before screening for the direct addition of aldehydes and ketones