Department of Chemistry, Indian Institution of Technology Kanpur, Kanpur 208016, Uttar Pradesh, India.
Org Lett. 2023 May 26;25(20):3733-3738. doi: 10.1021/acs.orglett.3c01198. Epub 2023 May 16.
A copper(II)-P,N,N-ligand catalyzed propargylic [3 + 2] cycloaddition approach for the synthesis of optically enriched dihydrofuro[3,2-]coumarins has been accomplished for the first time. The cycloaddition utilizes propargylic esters as C2-bis-electrophiles and 4-hydroxycoumarin derivatives as C,O-bis-nucleophiles. In addition, this novel strategy was also explored with 4-hydroxy-2-quinolinones and 4-hydroxythiocoumarins. Moreover, various dihydrofuro[3,2-]coumarins and their quinolinone and thiocoumarin analogues were synthesized in moderate to good yields with high enantioselectivities.
首次实现了铜（II）-P，N，N-配体催化的丙炔基[3 + 2]环加成方法，用于合成对映体富集的二氢呋喃并[3,2-c]香豆素。该环加成反应利用丙炔酸酯作为 C2-双亲电试剂和 4-羟基香豆素衍生物作为 C，O-双亲核试剂。此外，还探索了该新策略与 4-羟基-2-喹啉酮和 4-羟基硫代香豆素的应用。此外，通过该策略可以以中等至良好的收率和高对映选择性合成各种二氢呋喃并[3,2-c]香豆素及其喹啉酮和硫代香豆素类似物。
