Selectivity switch in the synthesis of vinylgold(I) intermediates
Type
ArticleAuthors
Hashmi, A. Stephen KSchuster, Andreas M.
Gaillard, Sylvain
Cavallo, Luigi

Poater, Albert

Nolan, Steven P.

KAUST Department
Biological and Environmental Sciences and Engineering (BESE) DivisionChemical Science Program
KAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Date
2011-11-28Permanent link to this record
http://hdl.handle.net/10754/561930
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Show full item recordAbstract
An unexpected regioselectivity reversal was observed in the synthesis of vinylgold(I) complexes from propargyl carboxamides. The use of [Au(IPr)(OH)] affords preferentially vinylgold(I) complexes resulting from a 5-exo-dig cyclization, whereas the use [Au(IPr)]+ species, generated in situ starting from [Au(IPr)(Cl)] and AgOTf, leads to vinylgold(I) complexes which form via a 6-endo-dig cyclization, This unexpected "selectivity switch" for this cyclization led us to propose two different reaction pathways enabling the formation of the two different products. One mechanism involves the [Au(IPr)]+ species with "classical" I activation of the alkyne framework of the carboxamides, and the second represents an "unusual" use of the basic Brønsted character of [Au(IPr)(OH)]. Mechanistic and DFT studies support the mechanistic hypotheses. © 2011 American Chemical Society.Citation
Hashmi, A. S. K., Schuster, A. M., Gaillard, S., Cavallo, L., Poater, A., & Nolan, S. P. (2011). Selectivity Switch in the Synthesis of Vinylgold(I) Intermediates. Organometallics, 30(22), 6328–6337. doi:10.1021/om2009556Sponsors
The ERC (FUNCAT to SPN) and the EPSRC are gratefully acknowledged for support of this work. A.P. thanks the Spanish MICINN for a Ramon y Cajal contract (RYC-2009-04170). Umicore AG and Chemetall AG are thanked for their generous gifts of materials. S.P.N. is a Royal Society Wolfson Research Merit Award holder. We thank Dr. Pierrick Nun for valuable discussions.Publisher
American Chemical Society (ACS)Journal
Organometallicsae974a485f413a2113503eed53cd6c53
10.1021/om2009556