Expedient synthesis of a symmetric cycloheptyne-Co2(CO)6 complex for orthogonal Huisgen cycloadditions

Abstract

A short procedure to prepare a cycloheptyne di-cobalt-carbonyl complex functionalised by a terminal alkyne is reported. This symmetric complex can react selectively in Strain Promoted Alkyne Azide Cycloaddition (SPAAC) or Copper Catalysed Alkyne Azide Cycloaddition (CuAAC) depending on the conditions, providing a new and practical tool for orthogonal conjugation reactions with azido reagents.