Copper-Catalyzed Coupling of Sulfonamides with Alkylamines: Synthesis of (E)-N-Sulfonylformamidines

Abstract

Herein, we describe an efficient copper-catalyzed coupling of sulfonamides with alkylamines to synthesize (E)-N-sulfonylformamidines. The reaction is accomplished under mild conditions without the use of a corrosive acid or base as an additive. It tolerates a broad scope of substrates and generates the products with exclusive (E)-stereoselectivity.

Copper‐Catalyzed Oxidative C−C Cleavage of Carbohydrates: An Efficient Access to Quinazolinone Scaffolds

“…In the alternative pathway, the initial step involves the formation of glucose fragmented products like formic acid F , and glycolic acid G through CuBr/DMSO catalyzed oxidative C−C cleavage [16d] . Next, these platform chemicals react with compound 1 to form imines H and I .…”

Copper-Catalyzed Regioselective C(sp3)—H Sulfonimidization of Aliphatic Cyclic Tertiary Amines

“…通过大范围的溶剂考 察, 均三甲苯为反应的最优溶剂, 获得产率为 87%的目 标产物 3aa(表 1, Entry 3). 根据我们前期的研究, 金属 铜催化剂对反应的成败至关重要 [10] . 标准条件移除铜 催化剂时, 目标产物 3aa 未曾被检测到(表 1, Entry 5).…”

“…161～162 ℃; 1 H NMR (600 MHz, Chloroform-d) δ: 8.19 (s, 1H), 7.79 (d,J＝8.3 Hz,2H),7.29 (d,J＝8.4 Hz,2H),3.78～3.72 (m,2H),3.68 (s,4H),3.49 (dd,J＝5.7,4.1 Hz,2H), 2.70 (q, J＝7.6 Hz, 2H), 1.26 (t, J＝7.6 Hz, 3H); 13 C NMR (150 MHz, Chloroform-d) δ: 157. 6, 148.9, 139.3, 128.3, 126.7, 66.8, 66.0, 50.3, 44.2, 28.8, 15.2. (E)-4-叔 丁 基 -N-( 吗 啉 亚 甲 基 ) 苯 磺 酰 胺 (3ca) [10] : 40.3 mg 白色固体, 产率 65%. m.p.…”

“…m.p. 162～163 ℃; 1 H NMR (600 MHz,1H),7.83～ 7.78 (m,2H),7.52～7.44 (m,2H),3.77～3.73 (m,2H),3.69 (s,4H),3.52～3.46 (m,2H),1.33 (s,9H); 13 C NMR (151 MHz,155.7,139.0,126.4,125.8,66.8,66.0,50.3,44.2,35.1,31.1. (E)-2-甲基-N-(吗啉亚甲基)苯磺酰胺(3da) [10] : 42.9 mg 白色液体, 产率 80%. 1 H NMR (600 MHz, Chloroform-d) δ: 8.19 (s, 1H), 8.01～7.97 (m, 1H), 7.41 (td, J＝…”

Rapid and efficient synthesis of formamidines in a catalyst-free and solvent-free system

“… 10 The second method is the reaction of sulfonamides with amines involving oxidation of the amine to an iminium cation generated electrochemically 11,12 or by reaction of Cu( ii ) (generated in situ by aerial oxidation of CuBr at 100 °C) ( Scheme 1b ). 13 The third method is cycloaddition of a sulfonyl azide to an enamine intermediate generated by oxidation of a trialkylamine followed by retrocycloaddition to generate a diazoalkane concomitantly ( Scheme 1c ). 14–16 The fourth method is a three-component reaction, reported previously by our research team, between a sulfonyl azide, a terminal ynone (3-butyn-2-one) and an amide involving the formation of a highly reactive intermediate N -sulfonyl acetylketenimine reacting with the amide in a [2 + 2] cycloaddition followed by a [2 + 2] cycloreversion with the concomitant generation of 4-oxo-3-buren-2-one ( Scheme 1d ).…”