Reactivity of the Sultam and Strained Alkyne Groups in 2‐Aminobenzenesulfonamide‐Containing Cyclononyne (ABSACN)

Abstract

2-Aminobenzenesulfonamide-containing cyclononyne (ABSACN), whichi saheterocycle that contains a sultam and strained alkyne group within the same ring, exhibits remarkable chemical reactivity in processes such as pyrrole transformations, Pauson-Khandc yclizations, click reactions, and Mitsunobu condensations. Herein, we introduce the synthesis and reactions of ABSACN, which focus on the sultam and alkyne functional groups, and study the unique characterization of prepared ABSACN derivativesb yN MR and X-ray crystallographic analyses. This work could lead to the efficient production of pharmaceutically relevant multiheterocyclic systemsb yu sing sequential cycloaddition reactions. ABSACN can also serve as ap otentialt emplate for multifunctional clickable alkyne reagents.Scheme1.Chemical transformationso fA BSACN (FG = functional group).[a] Dr. Scheme2.Preparation of N-alkynylsulfonamidesScheme3.Nitroarenereduction, cobalt complexation, and Nicholas cyclization reaction sequence.Scheme4.Nitroarenereduction of alkyne-cobalt carbonyl complex 27.Scheme5.Formation of maleic anhydride.Scheme6.Liberation of the cobalt complex.Scheme7.Pyrrole transformation.Scheme8.Strain-promotedP auson-Khand cycloaddition.Scheme9.SequentialSPAAC/Mitsunobu cycloaddition.