Synthesis of 4-Chloroisocoumarins via Intramolecular Halolactonization of <i>o</i>-Alkynylbenzoates: PhICl<sub>2</sub>-Mediated C–O/C–Cl Bond Formation
                                
                                    
                                        作者:Linlin Xing、Yong Zhang、Bing Li、Yunfei Du                                    
                                    
                                        DOI:10.1021/acs.orglett.9b00047
                                    
                                    
                                        日期:2019.4.5
                                    
                                    A series of 4-chloroisocoumarins were conveniently synthesized from o-alkynylbenzoates via PhICl2-mediated intramolecular cyclization under metal-free conditions. PhICl2 plays the role of both the oxidant and the chlorine source to enable oxidative C-O bond formation and introduction of the chlorine atom. The utility and practicability of this protocol have been exemplified by virtue of mild reaction conditions, high-yielding products, simplified purification, and gram-scale synthesis.