Less sterically crowded 2-(2-trimethylstannyl-3-thienyl)-1,3-dioxolane (4) was prepared and coupled with tert-butyl N-(ortho-halothienyl) carbamates, catalyzed by Pd(0) complex, to give dithieno[3,2-b; 2′,3′-d] pyridine (5), dithieno[3,4-b; 2′,3′-d]pyridine (6), and dithieno[2,3-b; 2′,3′-d]pyridine (7) in good yields.
在Pd(0)配合物的催化下,制备了空间位阻较小的2-(2-
三甲基锡烷基-3-
噻吩基)-
1,3-二氧戊环(4),并将其与叔丁基N-(邻卤代
噻吩基)
氨基甲酸酯偶联,得到二
噻吩并[3,2-b;2′,3′-d]
吡啶(5)、二
噻吩并[3,4-b;2′,3′-d]
吡啶(6)和二
噻吩并[2,3-b;2′,3′-d]
吡啶(7),产率较高。