The functionality of biomacromolecules has stimulated the development of stereocontrolled biomimetic oligomers for diverse functional applications. Here we report the synthesis of one novel sequence-defined oligotriazole architecture with excellent stereoregularity from 1,2,3-triazole-based chiral monomers. The facile introduction of broad side chains into this skeleton is enabled by the easy preparation of these building blocks from the efficient reaction of one L-prolinol-derived azide with various internal 1thioalkynes under mild iridium-catalyzed azide−alkyne cycloaddition (IrAAC) conditions. Assembly of them into desired oligomers could be achieved through metal-free iterative sequential or exponential growth strategies, the efficiency of which was demonstrated by the construction of three stereocontrolled oligotriazoles bearing different chain lengths and side groups. The structure and monodispersity of these oligomers were well characterized by 1 H NMR, SEC, MS, and tandem MS/MS analysis, and their stereoregularity was identified by circular dichroism.

As an indispensable part of click chemistry, thiol-yne reactions are of great importance in organic and material synthesis. Nevertheless, efficient strategies for the addition of thiols onto internal alkynes with excellent regio- and stereocontrol are still scarce. Here we report the regio- and stereospecific hydrothiolation of electron-rich thioalkynes facilitated by organic base additive, which could proceed exceedingly fast under ambient atmosphere and room temperature, affording beta trans addition products in up to nearly quantitative yields. The dual nature of sulfur atom in attracting and donating electrons is supposed to be pivotal in determining the regio- and stereospecificity. This system tolerates a wide scope of thiols and thioalkynes, and shows great potential in polymer synthesis. In combination of its excellent performance in diverse environmentally benign solvents, especially in water/dimethyl sulfoxide mixtures that are usually used in bio-related research, applications of this newly established click reaction in diverse fields are highly expected.