Modular Synthesis of Triazole-based Chiral Iodoarenes for Enantioselective Spirocyclizations

A new triazole-based C1-symmetric chiral iodoarene was synthesized in a highly modular route. Based on enzymatic kinetic resolution of an easy accessible propargylic alcohol both enantiomers were accessible in enantiopure form. By Huisgen-type azide-alkyne cycloaddtion a series of differently substituted iodoarenes were synthesized in high overall yields. Finally this novel iodoarene was successfully applied in the oxidative Kita cyclization of naphthol derivatives. Good yields and high ee values were obtained in the asymmetric spirocyclyzation via in situ generation of the hypervalent iodine species using mCPBA as the terminal oxidant.