Studies On The Radical-Mediated Sulfone Formation Reactions From Aryl Diazonium Salts

Sulfone-based structure motifs are widely found in natural products,drugs as well as material molecules.Among them,cyclic sulfones and chiral sulfones tend to have excellent biological or pharmaceutical activities in the treatment of diseases,reduction of pain,and improvement of patients’quality of life.Aryl diazonium salts play a major role in building chemical bonds such as C-S,C-B,C-P,C-Sn and C-CF₃of organic compound molecules,and the development of diazonium chemistry also provides a new strategy for the synthesis of pharmaceutically active substances.In this paper,the methods for the rapid construction of sulfonated pyrrolidones and chiral sulfones based on aryl diazonium salt participation and sulfur dioxide insertion protocols are investigated.Part Ⅰ:the recent research progress in the insertion reactions of aryl diazonium salts with radical type"SO₂"was briefly reviewed.Meanwhile,the radical-type asymmetric synthetic reactions toward chiral sulfones and their related mechanisms are elucidated.Part Ⅱ:an efficient method to prepare sulfonylated pyrrolidones based on diazonium salts initiated radical type SO₂ insertion was reported.A series of substituted sulfonylated pyrrolidone compounds were obtained in moderate to excellent yields from this reaction.The product structure was confirmed by single crystal X-ray diffraction analysis.The reaction requires no metal participation,has mild conditions and is green and economical.Part Ⅲ:a photo induction Truce-Smiles rearrangement reaction was developed to prepare chiral sulfone compounds bearing a chiral quaternary carbon center from aryl diazonium salts and sulfur dioxide surrogate.This reaction was capable of generating functionalized sulfonyl radical species from readily available starting materials under mild conditions,thus providing a new strategy for the synthesis of chiral quaternary carbon sulfones.