Stereodivergent Alkyne Hydrofluorination Using Protic Tetrafluoroborates as Tunable Reagents
作者:Rui Guo、Xiaotian Qi、Hengye Xiang、Paul Geaneotes、Ruihan Wang、Peng Liu、Yi‐Ming Wang
DOI:10.1002/anie.202006278
日期:2020.9.14
available precursors remains a synthetic challenge. The metal‐free hydrofluorination of alkynes constitutes an attractive though elusive strategy for their preparation. Introduced here is an inexpensive and easily handled reagent that enables the development of simple and scalable protocols for the regioselective hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These
Enantioselective Synthesis of β-Fluoro-β-aryl-α-aminopentenamides by Organocatalytic [2,3]-Sigmatropic Rearrangement
作者:Kevin Kasten、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/acs.orglett.7b02452
日期:2017.10.6
The tetramisole-promoted catalytic enantioselective [2,3]-sigmatropic rearrangement of quaternary ammonium salts bearing a (Z)-3-fluoro-3-arylprop-2-ene group generates, after addition of benzylamine, a range of β-fluoro-β-aryl-α-aminopentenamides containing a stereogenic tertiary fluorine substituent. Cyclic and acyclic nitrogen substituents as well as various aromatic substituents are tolerated,
Enantioselective Allenoate-Claisen Rearrangement Using Chiral Phosphate Catalysts
作者:Javier Miró、Tobias Gensch、Mario Ellwart、Seo-Jung Han、Hsin-Hui Lin、Matthew S. Sigman、F. Dean Toste
DOI:10.1021/jacs.0c01637
日期:2020.4.1
Herein we report the first highly enantioselective allenoate-Claisen rearrangement using doubly-axially chiral phosphate sodium salts as catalysts. This synthetic method provides access to β-amino acid derivatives with vicinal stereocenters in up to 95% ee. We also investigated the mechanism of enantioinduction by transition state computations with DFT as well as statistical modeling of the relationship