C–H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
作者:Bradley J. Gorsline、Long Wang、Peng Ren、Brad P. Carrow
DOI:10.1021/jacs.7b03887
日期:2017.7.19
catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C–H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C–H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples)
Gold Catalysis: Dihydroisobenzofurans and Isochromanes by the Intramolecular Furan/Alkyne Reaction
作者:A. Stephen K. Hashmi、M. Wölfle、Filiz Ata、Melissa Hamzic、Ralph Salathé、Wolfgang Frey
DOI:10.1002/adsc.200600367
日期:2006.11
furyl alcohols and homofuryl alcohols was synthesized by reduction of furfurals or reaction of furyllithium compounds with epoxides and subsequent propargylation. The gold-catalyzed cycloisomerization of these products furnished dihydroisobenzofurans and isochromanes. Crystal structure analyses proved the sequence of the substituents for both classes of products. Unsaturated dicarbonyl compounds as side-products
作者:A. Stephen K. Hashmi、Melissa Hamzić、Frank Rominger、Jan W. Bats
DOI:10.1002/chem.200901695
日期:2009.12.14
Selecting one out of two enantiotopic alkynes: A furan–diyne substrate with enantiotopic alkynyl groups was prepared and the gold‐catalyzed cycloisomerization by a series of different chiral cationic gold(I) complexes was investigated (see scheme).
Gold Catalysis: Efficient 1,3-Induction with Diastereotopic Homopropargyl Alcohols in the Phenol Synthesis
作者:A. Stephen K. Hashmi、Melissa Hamzić、Matthias Rudolph、Martin Ackermann、Frank Rominger
DOI:10.1002/adsc.200900402
日期:2009.10
Furans with diastereotopic alkynyl groups were prepared and then converted to anellated phenols in gold-catalyzed reactions. In all cases a highly diastereoselective reaction was observed. The stereochemical outcome of the 1,3-induction could be assigned by two independent crystal structure analyses, showing a cis-arrangement of the two alkyl substituents on the benzoanellated cyclohexene ring.