Selective Conversion of Unactivated C–N Amide Bond to C–C bond via Steric and Electronic Resonance Destabilization

Abstract

The chemo- and site-selective reaction at the particular C–N amide bond among a sea of other amides is a significant and long-standing challenge. Although the use of twisted amides has been demonstrated for modifications of inert C–N amide bonds, none of these methods can selectively activate a particular amide bond for C–C bond formation in the presence of similar amides. Using density functional theory as a guide, we report the first site-selective C–C bond modification of a particular C–N amide bond in polyamides with a low twist angle by combining ground-state steric distortion with electronic activation.

Regioselective Coordination toward Silver(I) Ions by Bis- and Tris(Tetra-Armed Cyclen)s via Differential Electron Density of Aromatic Side Arms

“…Mp 242−243 °C; 1 H NMR (400 MHz, CDCl 3 ) δ 6.73−6.69 (m, 6H), 4.29 (dt, J 1 = 13.9 Hz, J 2 = 4.0 Hz, 2H), 4.08 (s, 2H), 3.61 (q, J = 5. 6 A mixture of 8 (0.774 g, 1.10 mmol), B 2 pin 2 (0.309 g, 1.22 mmol), Pd(dppf)Cl 2 (CH 2 Cl 2 adduct, 58 mg, 71 μmol), and KOAc (0.360 g, 3.67 mmol) in 1,4-dioxane (10 mL) was stirred for 24 h at 100 °C under a nitrogen atmosphere. After the reaction mixture was filtrated and evaporated, the residue (compound 9) was mixed with 10 (0.719 g, 1.00 mmol), Na 2 CO 3 (0.360 g, 3.40 mmol), and Pd(dppf)Cl 2 (CH 2 Cl 2 adduct, 41 mg, 50 mmol) in 1,4-dioxane:H 2 O (10 mL, 4:1), and the mixture was stirred for 24 h at 100 °C under a nitrogen atmosphere.…”

“…It is crucial to control the regioselectivity of the substitution to produce specific reaction products with desired properties. Regioselectivity plays an important role in many areas of organic chemistry, including synthesizing pharmaceuticals and elucidating their mechanisms of action. − In other words, regioselectivity in organic chemistry is important for controlling reactions, improving synthetic efficiency, and advancing fields such as pharmaceuticals and organic electronics. While there are examples of regioselective reactions in inorganic and coordination chemistry, they are less common than in organic chemistry .…”

Catalyst-free activation of N–C(O) Amide bonds – efficient cascade synthesis of N-acyl thiocarbamides in batch and continuous-flow

“…[6][7][8][9] Among amide bond activation strategies, the potential use of electronically dynamic or structurally twisted amides as acylating agents through N-C bond cleavage has undergone numerous transformations under transition-metal and metal-free conditions. [10][11][12][13][14][15][16] Over the last decade, amides have been crucial as donors for acyl or alkyl groups. [17][18][19] A multitude of acyl sub-stitution reactions involving amides have been developed, facilitating the synthesis of amides, 20 esters, 16,21,22 and ketones.…”