Metal-free and efficient approach to 4-thiocyanated 2H-chromenes via TFA-mediated cascade cyclization of 2-propynolphenols. Issue 18 (2nd May 2019)

• Record Type: Journal Article
• Authors: Yang, Tao; Song, Xian-Rong; Li, Ren; Jin, Fengyan; Zhang, Yuxing; Bai, Jiang; Yang, Ruchun; Ding, Haixin; Xiao, Qiang
• Is Part Of: Tetrahedron letters. Volume 60:Issue 18(2019)
• Page Start: 1248
• Page End: 1253
• Publication Date: 2019-05-02
• Subjects: 2-Propynolphenols -- 4-Thiocyanated 2H-chromenes -- TFA-mediated -- Cascade cyclization; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2019.03.070
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: TFA mediated synthesis of 4-thiocyanated 2 H -chromenes in good to excellent yields. The 4-thiocyanated 2 H -chromenes are versatile intermediates in organic synthesis. This approach can be enlarged to gram scale. This process involves a SCN-containing alleneyl intermediate through SN 1 way. Abstract: A metal-free, Brønsted acid-mediated cascade cyclization of 2-propynolphenols for efficient synthesis of various 4-thiocyanated 2 H -chromenes is developed by using KSCN as the thiocyanated source. This reaction was characterized by readily prepared starting materials, bearing good functional group tolerance and excellent yields. Moreover, the obtained 4-thiocyanated 2 H -chromenes could be further derivated to potential bioactive and pharmaceutical molecules.