Two closely related {4-[(N-substituted amino)(diethoxyphosphoryl)methyl]phenyl}boronic acids

Abstract

Organic phosphonic acids and organic phosphonic acid esters have been of much interest due to their applications in the fields of medicine, agriculture and industrial chemistry. Boronic acids can act as synthetic intermediates and building blocks and are used in sensing, protein manipulation, therapeutics, biological labelling and separation. The additional introduction of an aminophosphonic acid group into a boronic acid may give new opportunities for application. To study the structure of such multifunctional compounds, we prepared two new derivatives which can be easily converted to the corresponding phosphonic acids. In the title compounds, {4-[(butylamino)(diethoxyphosphoryl)methyl]phenyl}boronic acid monohydrate, CHBNOP·HO, (I), and {4-[(diethoxyphosphoryl)(4-nitroanilino)methyl]phenyl}boronic acid, CHBNOP, (II), three different substituents are attached to a central C-H group, namely 4-boronophenyl, diethoxyphosphoryl and amine. Compound (I) crystallizes as a monohydrate and O-H...N hydrogen bonds link neighbouring molecules into chains along the [001] direction. The solvent water molecule connects two such chains running in opposite directions. Compound (II) crystallizes as an ansolvate and classical hydrogen bonds result in a layer structure in the (001) plane.

Exploration of the Luminescence Properties of Organic Phosphate Salts of 3‐Quinoline‐ and 5‐Isoquinolineboronic Acid

“…As in 3QBA‐1NP and 5IQBA‐1NP , in the cation the ‐B(OH) 2 group adopts the syn,syn ‐conformation with a slight twist of the BO 2 mean plane in relation to the quinoline ring plane (7.2°), favoring the formation of a double‐bridged heterodimer linked via two O‐H ··· O hydrogen bonds, employing the terminal –PO 2 – group of the phosphate anion and the –B(OH) 2 segment (Scheme , synthon A ) . The heterodimers are composed of 8‐membered rings corresponding to the graph set R 2 2 (8) with O1 ··· O3 and O2 ··· O4 distances of 2.673(2) and 2.837(2) Å …”

“…With strong acceptor groups, boronic acids can form strong double‐bridged hydrogen bonding synthons such as the ‐B(OH) 2 ··· – OOC motif formed with carboxylate groups . Although this capability has received attention for applications in molecular recognition, [25] structurally related heterodimeric synthons with other anions such as halides, sulfates/sulfonates and phosphate/phosphonates are practically unexplored.…”