An efficient dehydrogenative Diels–Alderreaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.
A metal‐free dehydrogenative Diels‐Alderreaction of substituted alkenes for the synthesis of tetrahydroisoindolinones has been exploited for the first time. This new method features functional group tolerance and broad substrate scope, providing an efficient access to biologically active tetrahydroisoindolinone skeletons with endo steroselectivity in good to excellent yields.
Enantioselective Folding of Enynes by Gold(I) Catalysts with a Remote <i>C</i><sub>2</sub>-Chiral Element
作者:Giuseppe Zuccarello、Joan G. Mayans、Imma Escofet、Dagmar Scharnagel、Mariia S. Kirillova、Alba H. Pérez-Jimeno、Pilar Calleja、Jordan R. Boothe、Antonio M. Echavarren
DOI:10.1021/jacs.9b06326
日期:2019.7.31
Chiral gold(I) catalysts have been designed based on a modified JohnPhos ligand with a distal C2-2,5-diarylpyrrolidine that creates a tight binding cavity. The C2-chiral element is close to where the C-C bond formation takes place in cyclizations of 1,6-enynes. These chiral mononuclear catalysts have been applied for the enantioselective 5-exo-dig and 6-endo-dig cyclization of different 1,6-enynes
A copper(I)/DDQ-mediated double-dehydrogenative Diels–Alder (DDDA) reaction of simple butenes with 1,4-diketones and indolones has been established for the first time. This strategy is based on a tandem double-dehydrogenation/Diels–Alderreaction from nonprefunctionalized starting materials, in which both a diene and dienophile were in situgenerated via activation of fourfold inert C(sp3)–H bonds