On the validity of Au-vinylidenes in the gold-catalyzed 1,2-migratory cycloisomerization of skipped propargylpyridines.
A mechanism of the Au-catalyzed cycloisomerization of propargylpyridines has been investigated. Both DFT computational and experimental results strongly support generation of a Au-carbene via a cyclization/proton transfer sequence over the previously proposed path involving a Au-vinylidene intermediate. For the β-Si-substituted Au-carbene (G = SiR(3)), a 1,2-Si migration was shown to be kinetically favored over a 1,2-H shift. This study highlights the importance of alternative pathways that could explain reactivities commonly attributed to an alkyne-vinylidene isomerization in Au catalysis.
Key Laboratory of Organic Synthesis of Jiangsu Province, Department of Chemistry and Chemical Engineering, Soochow University, Suzhou 215006, China.
Yuanzhi
Y
Xia
Alexander S
AS
Dudnik
Yahong
Y
Li
Vladimir
V
Gevorgyan
D002384:Catalysis; D003500:Cyclization; D006046:Gold / Q000737:chemistry*; D007192:Indenes / Q000737:chemistry*; D007536:Isomerism; D015394:Molecular Structure; D009019:Morphinans / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D014753:Vinyl Compounds / Q000737:chemistry*
D007192:Indenes; D009019:Morphinans; C440369:N-propargyl; D011725:Pyridines; D014753:Vinyl Compounds; C545570:vinylindene; D006046:Gold; C023666:pyridine