145208-53-3Relevant academic research and scientific papers
Gold-catalyzed oxidative coupling of arylsilanes and arenes: Origin of selectivity and improved precatalyst
Ball, Liam T.,Lloyd-Jones, Guy C.,Russell, Christopher A.
supporting information, p. 254 - 264 (2014/01/23)
The mechanism of gold-catalyzed coupling of arenes with aryltrimethylsilanes has been investigated, employing an improved precatalyst (thtAuBr3) to facilitate kinetic analysis. In combination with linear free-energy relationships, kinetic isotope effects, and stoichiometric experiments, the data support a mechanism involving an Au(I)/Au(III) redox cycle in which sequential electrophilic aromatic substitution of the arylsilane and the arene by Au(III) precedes product-forming reductive elimination and subsequent cycle-closing reoxidation of the metal. Despite the fundamental mechanistic similarities between the two auration events, high selectivity is observed for heterocoupling (C-Si then C-H auration) over homocoupling of either the arylsilane or the arene (C-Si then C-Si, or C-H then C-H auration); this chemoselectivity originates from differences in the product-determining elementary steps of each electrophilic substitution. The turnover-limiting step of the reaction involves associative substitution en route to an arene π-complex. The ramifications of this insight for implementation of the methodology are discussed.
Novel Immunosuppressive Butenamides
Axton, Christopher A.,Billingham, Michael E. J.,Bishop, Paul M.,Gallagher, Peter T.,Hicks, Terence A.,et al.
, p. 2203 - 2214 (2007/10/02)
2-thiophene 12 was carboxylated using butyllithium and carbon dioxide to give 5-thiophene-2-carboxylic acid 13.Conversion of the acid 13 using diphenyl phosphazidate and triethylamine gave 5-4-(1,
