Mild Reductive Functionalization of Amides into N‐Sulfonylformamidines

Abstract

The development of a protocol for the reductive functionalization of amides into N‐sulfonylformamidines is reported. The one‐pot procedure is based on a mild catalytic reduction of tertiary amides into the corresponding enamines by the use of Mo(CO)6 (molybdenum hexacarbonyl) and TMDS (1,1,3,3‐tetramethyldisiloxane). The formed enamines were allowed to react with sulfonyl azides to give the target compounds in moderate to good yields.

Advances in the Synthesis of N-Sulfonyl Amidines

“…该中间体与酰胺 [2＋2]环加成, 并脱羧形成目标产物(Scheme 21). Adolfsson 小组 [43] 以 Mo(CO) 6 为羰基源, 在 1,1,3,3-四甲基二硅氧烷(TMDS)辅助下, 以乙酸乙酯作溶剂, 在 60 ℃也实现了类似通过磺酰叠氮和酰胺直接反应合 成 N-磺基脒的方法(Eq. 7)…”

Mechanochemical Metal‐free N‐Sulfonyl Transfer Reaction: Expedient Synthesis of N‐Sulfonyl Amidines

“…Their biological importance has prompted numerous synthetic protocols to access them. The reported synthesis of N‐sulfonyl amidines begin either from sulfonyl azides or sulfonamides [23–51] . For example a copper catalyzed three component reactions of sulfonyl azides, terminal alkynes and amines (Scheme 1a) afforded the desired N‐sulfonyl amidine via a sulfonyl ketenimine intermediate [23] .…”

Metal-Free Direct Access toN-Sulfonyl Amidines from Sulfonamides and Secondary Amines Involving Tandem C–N Bond Formations

“…Huang and Hu disclosed a three-component reaction between a sulfonyl azide, terminal ynone, and amide to synthesize N -sulfonyl amidines via the N -sulfonyl acetylketenimine intermediate (Scheme c). Mo­(CO) 6 -catalyzed reductive functionalization of amides to enamines and the subsequent reaction with sulfonyl azides provided N -sulfonyl formamidines (Scheme c) . The synthetic route to cyclic N -sulfonyl amidines was developed via iridium-catalyzed one-pot deoxygenative reduction of lactams with a silane followed by a cycloaddition reaction with sulfonyl azides (Scheme c) .…”