Metalated Sulfonamides and their Synthetic Applications

Abstract

Benzenesulfonamide is a powerful Directed Metalation Group (DMG) whose great potentials are yet to be fully explored. This account highlights some of the vast possibilities inherent in arylsulfonamides using the Directed ortho Metalation (DoM) methodology. It shows some of the products of metalation and their applications in heterocyclic synthesis. Concomitant rearrangements and new developments are also presented.3.12 Preparation of 2-Benzothiazocine and 2-Benzothiazacyclopentadecine 3.13 Synthesis of 2-Benzoxathiazonine-1,1-dione 4.0 Conclusion

Directedortho-Metalation–Cross-Coupling Strategies. One-Pot Suzuki Reaction to Biaryl and Heterobiaryl Sulfonamides

“…The original and significant directed ortho -metalation (D o M) work on aryl sulfonamides 1 reported by Hauser et al coupled with our interest to fortify and expand the metalation chemistry of these systems 2 and the growing prevalence of the sulfonamide pharmacophore in medicinal agents (Figure ) , has prompted further investigations of this powerful directed metalation group (DMG) in carbanionic aromatic and heteroaromatic reactions and its impact in further synthetically useful processes. , …”

Structure and reactivity of new phosphine ligands containing the hemi-labile sulfone moiety

“…The oxygen is predicted to be hemilabile and thus rotation about the P-[M] bond is expected to occur. A number of publications have investigated ortho-lithiation of sulfonamides, as reviewed by Familoni, 7 and these reports indicate that aryl sulfonamides (like aryl ethers) are ortho directing. Thus ligand 1 was prepared in 67% yield by the reaction of diphenyl sulfone 6 with two equivalents of n-butyllithium in tetrahydrofuran at −78 • C followed by the dropwise addition of dichlorophenylphosphine in tetrahydrofuran (Scheme 1).…”

2 Synthetic methods : Part (iv) Heteroatom methods

“…38 Luh has written a mini-review of synthetic applications of dithioacetals. 39 These functional groups are familiar as umpolung synthons (25, see below), but Luh focuses on their silylolefination under nickel catalysis, a reaction in which they perform as gem-dication synthons (26) and which has been employed for the synthesis of silylsubstituted alkenes for optoelectronics applications, e.g. the paracyclophane 27 (Scheme 11).…”