Cu(I)-catalyzed azide-alkyne cycloaddition, considered as a “click chemistry”, has been used in many fields of chemistry, including chemical biology. But, because of cytotoxicity of Cu(I), applications of this reaction for living systems have been restricted. Cyclooctyne which has high ring strain energy reacts with azide without Cu(I) catalyst. This reaction is often called “copper-free click chemistry (CFCC)”. This short review summarizes the recent advance in CFCC using cyclooctynes.
2012 社団法人 有機合成化学協会