Highly Selective and Catalytic C–N Bond Cleavage of Tertiary Sulfonamides: Scope and Mechanistic Insight

Abstract

A highly chemoselective C–N bond cleavage reaction of p-methoxybenzyl- (PMB), 3,4-dimethoxybenzyl- (DMB), or cinnamyl-substituted tertiary sulfonamides in the presence of catalytic Bi­(OTf)3 is presented. A wide range of sulfonamide substrates smoothly furnished the corresponding C–N bond cleavage products in good to excellent yields. Great efforts have been made to obtain insights into the reaction mechanism based on a series of control experiments and mass spectroscopy.

Light-Driven Reductive Cleavage of Sulfonamides Promoted by Thiourea Organophotosensitizers

“…19 F NMR (471 MHz, CDCl 3 ): δ −114.3 (F) ppm. Spectroscopic data were consistent with the literature data for this compound …”

“…Spectroscopic data were consistent with the literature data for this compound. 40 Compound S6. According to the representative procedure, starting from 4-methoxybenzylamine (1 equiv, 0.…”

Chemoselective Cleavage of Acylsulfonamides and Sulfonamides by Aluminum Halides

“…This strategy, after attaching a solubility-modifying group to either the sulfonyl or acyl end, has been widely applied in solid-phase peptide synthesis (Scheme A) . Although sulfonamides could be N-dealkylated by a number of protocols such as chromium­(III) acetate-periodic acid, PhI­(OAc) 2 /I 2 under ultrasonic irradiation, electrolysis under oxidizing electrosynthetic conditions, N-debenzylation by Cu­(MeCN) 4 PF 6 under Chan–Lam conditions or by an alkali bromide/oxidant system, deprotection of p -methoxybenzyl from tertiary sulfonamides by bismuth triflate, and removal of diphenylmethyl by Pd­(OH) 2 under an atmosphere of hydrogen gas, few approaches are available for N-dealkylation of tertiary acylsulfonamides. This is seemingly due to competitive deacylation activated by the N -alkyl substituent.…”