This protocol selectively provides a straightforward route to prepare ortho-(1-alkynyl) benzenesulfonamides or six-membered benzosultams by using different silyl protected bromoalkynes.

We developed herein an iridium-catalyzed direct CÀ H activation/ CÀ N bond formation reaction of benzenesulfonamides with sulfonyl azides. The amidation reaction provides a protocol for the synthesis of 2-aminobenzesulfonamides in good to excellent yields. This strategy features a wide substrate scope, tolerates a broad range of functional groups under external oxidant-free conditions and only releases molecular nitrogen as the sole by-product. Moreover, the preliminary mechanism was investigated and the proposed reaction pathway was provided. Figure 1. Selected biologically active benzothidiazine-1,1-dioxides containing the 2-aminobenzenesulfonamides motif.

Selective C–H bond alkynylation toward modular access to material and pharmaceutical molecules is of great desire in modern organic synthesis. Disclosed herein is rhodium(III)‐catalyzed selective C–H bond mono‐/bialkynylation of 4‐aryl phthalazin‐1(2H)‐one was developed. The silver salt AgSbF6 are demonstrated to play a vital role in promoting the bialkynylation reactions. The present alkynylation strategy is simple, efficient, and features high functional group tolerance and broad substrate scope under an air atmosphere. Additionally, 6‐aryl pyridazin‐3(2H)‐one scaffold is amenable to the selective monoalkynylation and sequential bialkynylation, respectively.