Silver-catalyzed [2 + 2] cycloadditions of siloxy alkynes.
We have described the first [2 + 2] cycloadditions of siloxy alkynes with a range of unsaturated carbonyl compounds. The reactions are efficiently promoted by substoichiometric amount of silver trifluoromethanesulfonimide and display excellent regio- and diastereoselectivity combined with a broad substrate scope. Our studies have established unambiguously the stepwise mechanism of this process and provided evidence for a novel role of silver in the catalytic cycle of the reaction, which involves silver-based complexation and activation of siloxy alkyne toward the subsequent 1,4-addition.
Sweis
Randy F
RF
University of Chicago, Department of Chemistry, 5735 South Ellis Ave, Chicago, Illinois 60637, USA.
Schramm
Michael P
MP
Kozmin
Sergey A
SA
D000480:Alkynes / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis*; D012834:Silver / Q000737:chemistry*
D000480:Alkynes; D017646:Organosilicon Compounds; D012834:Silver