Advanced Research Institute and Department of Chemistry;
Taizhou University;
Taizhou 318000;
China;
Department of Chemistry;
Zhejiang Sci-Tech University;
Hangzhou 310018;
China;
Department of Chemistry;
Zhejiang University;
Hangzhou 310058;
China;
Difluorinated chromans; 4+2Cyclization; Difluoroenoxysilanes; HFIP catalysis; Diastereoselectivity;