Apparent copper(II)-accelerated azide-alkyne cycloaddition.
Cu(II) salts accelerate azide-alkyne cycloaddition reactions in alcoholic solvents without reductants such as sodium ascorbate. Spectroscopic observations suggest that Cu(II) undergoes reduction to catalytic Cu(I) species via either alcohol oxidation or alkyne homocoupling, or both, during an induction period. The reactions involving 2-picolylazide are likely facilitated by its chelation to Cu(II). The highly exothermic reaction between 2-picolylazide and propargyl alcohol completes within 1-2 min in the presence of as low as 1 mol % Cu(OAc)(2).
Brotherton
Wendy S
WS
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA.
Michaels
Heather A
HA
Simmons
J Tyler
JT
Clark
Ronald J
RJ
Dalal
Naresh S
NS
Zhu
Lei
L
D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D015394:Molecular Structure; D010084:Oxidation-Reduction; D020005:Propanols / Q000737:chemistry; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
D000480:Alkynes; D001386:Azides; D020005:Propanols; D014230:Triazoles; D003300:Copper; C028255:propargyl alcohol