A significant role of alkaline cations on the Reimer–Tiemann reaction

Abstract

The Reimer-Tiemann (R-T) reaction was investigated by DFT calculations. A model composed of CHCl(3), PhO(-)(Na(+))H(2)O and [NaOH(H(2)O)(2)](2) was employed for geometry optimizations. A K(+)-containing model was also investigated. The dichlorocarbene reagent, which has been thought of for a long time, was found to intervene only transiently in the carbenoid form. In this form, the Na(+) (or K(+)) coordination to CCl(2) enhances its electrophilicity toward C(6)H(5)O(-). The counter ion also works to stabilize the precursor phenoxide ion and intermediates of the substituted phenoxides in the hexagonal pyramidal coordination. The Na(+)-containing reaction consists of seven elementary processes, (K(+), six ones) with extremely high exothermicity and spontaneity.

A New Route for the Synthesis of the Repaglinide Key Intermediate 3-Ethoxy-4-Ethoxycarbonylphenylacetic Acid

“…In this step, 14 could be obtained from 13 by Duff formylation. [16][17][18][19][20][21][22][23][24] from water. However, for Duff formylation of 13, the influence of a small amount of water can almost be neglected and even 80-90% acetic acid aqueous solution allowed the reaction to proceed.…”

Metal-free selective aryl C–H formylation co-controlled by 1,2,3-triazole and hydroxyl using DMSO as formyl source

“…1,2 Due to the remarkable application value in chemistry, formylation of arene has attracted much interest of organic chemists. Traditionally, the most classical methods include Vilsmeier-Haack, [3][4][5] Duff reaction, [6][7][8] Reimer Tiemann, 9,10 Rieche 11 and Friedel-Crafts acylations. 12,13 Nevertheless, these reactions generally require excess strong bases or acids in workup processes and are unfriendly to the environment.…”