Rhodium-catalyzed direct C–H bond alkynylation of aryl sulfonamides with bromoalkynes

Abstract

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

Palladium‐Catalyzed ortho‐Benzoylation of Sulfonamides through C−H Activation: Expedient Synthesis of Cyclic N‐Sulfonyl Ketimines

“…Unfortunately, the Pd-catalyzed CÀ H activation failed with N-methoxy-4-nitrobenzenesulfonamide (2 k) with complete recovery of starting material, probably due to ring deactivation by the nitro group (Table 2, entry 11). Further, by extending the substrate scope of the carbonylation reaction with differently substituted aryl aldehydes gave the corresponding benzoylated derivatives in moderate yields (entries [12][13][14][15][16][17][18][19][20][21]. Interestingly, the halogen-substitutions in the aldehydes as well as sulfonamides were compatible to the optimal reaction conditions and exhibit the desired product in appreciable yield.…”

Recent Advances in Catalytic Synthesis of Benzosultams

“…Encouraged by these works, Chen and co-workers achieved a rhodium-catalyzed ortho -alkynylation or alkynylation/cyclization of arylsulfonamides, synthesizing an array of aryl sulfonamides and benzosultams ( Scheme 5 ) [ 61 ]. The substituent in bromoalkyne has a significant effect on this reaction.…”

Iridium‐Catalyzed ortho‐C−H Amidation of Benzenesulfonamides with Sulfonyl Azides

“…A kH/kD value of 1.3 was observed, the value differs significantly from the KIE of 2.6 that was determined for a similar reaction. [24] As Table 2. Substrate scope of aryl sulfonamides and aryl sulfonyl azides in the CÀ H amidation.…”

“…[23] More recently, we have developed an efficient Rh-catalyzed direct orthoalkynylation of aryl sulfonamides with bromoalkyne, affording the 2-alkynylated arylsulfonamides. [24] Despite this progress, to the best of our knowledge, transition metal-catalyzed direct ortho-CÀ H amidation of benzenesulfonamides has not been reported. Herein, we report an efficient and broadly applicable protocol for the synthesis of 2-sulfonylaminobenzylsulfonamides via Ir-catalyzed ortho-C(sp 2 )-H amidation of benzenesulfonamides with aryl sulfonyl azides.…”

“…Recently, You reported an alternative method for synthesis of biaryl sulfonamide via Rh‐catalyzed oxidative C−H/C−H cross‐coupling of aromatic sulfonamides with arenes . More recently, we have developed an efficient Rh‐catalyzed direct ortho ‐alkynylation of aryl sulfonamides with bromoalkyne, affording the 2‐alkynylated arylsulfonamides . Despite this progress, to the best of our knowledge, transition metal‐catalyzed direct ortho ‐C−H amidation of benzenesulfonamides has not been reported.…”