ABSTRACT An N ‐heterocyclic carbene (NHC)‐catalyzed 3+3 annulation of δ ‐acetoxy allenoates with 2‐acylbenzothiazoles has been developed. This dearomative annulation methodology provided a facile method for the synthesis of benzo4,5thiazolo3,2‐ a pyridine derivatives with a broad substrate scope in moderate to good yields (24 examples, up to 74% yield).
Zhang et al. (Thu,) studied this question.