Facile synthesis of α-aminophosphine oxides from diarylphosphine oxides, arynes and formamides

TEMPO/O2 Synergistically Mediated BiBrO-Photocatalyzed Decarboxylative Phosphorylation of N-Arylglycines

With both TEMPO and O2 (in air) as the homogeneous redox mediators, BiBrO as the heterogeneous semiconductor photocatalyst, the first example of semi-heterogeneous photocatalytic decarboxylative phosphorylation of N-arylglycines with diarylphosphine oxides was established. A series of α-amino phosphinoxides were efficiently synthesized.

Imidazoles are Tunable Nucleofuges for Developing Tyrosine-Reactive Electrophiles

Imidazole-1-sulfonyl and -sulfonate (imidazylate) are widely used in synthetic chemistry as nucleofuges for diazotransfer, nucleophilic substitution, and cross-coupling reactions. The utility of these reagents for protein bioconjugation, in contrast, have not been comprehensively explored and important considering the prevalence of imidazoles in biomolecules and drugs. Here, we synthesized a series of alkyne-modified sulfonyl- and sulfonate-imidazole probes to investigate the utility of this electrophile for protein binding. Alkylation of the distal nitrogen activated the nucleofuge capability of the imidazole to produce sulfonyl-imidazolium electrophiles that were highly reactive but unstable for biological applications. In contrast, arylsulfonyl imidazoles functioned as a tempered electrophile for assessing ligandability of select tyrosine and lysine sites in cell proteomes and when mated to a recognition element could produce targeted covalent inhibitors with reduced off-target activity. In summary, imidazole nucleofuges show balanced stability and tunability to produce sulfone-based electrophiles that bind functional tyrosine and lysine sites in the proteome.

TEMPO/PhI(OAc)2 promotes the α-aminophosphinoylation of alcohols with amines and H-phosphine oxides in aqueous medium

A novel method for synthesizing α-aminoalkyl phosphine oxides in aqueous medium, using Ar2P(O)-H reagents, alcohols and amines, is described. This method: (i) allows for the smooth aminophosphinoylation of alcohols with amines and H-phosphine oxides under mild conditions; (ii) provides an efficient and alternative approach to access various α-aminoalkylphosphine oxides. Although various amines exhibited remarkable versatility and tolerance for functional groups in this reaction, alcohols and H-phosphine oxides demonstrated limited applicability as reactants. Hence, further investigation using a wider range of substrates is crucial. The postulated mechanism indicated that the three-component reaction followed the imine pathway due to the in situ oxidation of alcohol to aldehyde.

Synthesis and antitumor activities of α-hydroxyamino phosphine oxides by catalyst-free hydrophosphinylation of nitrones

Inspired by the diverse bioactivities of α-amino phosphine oxides, an efficient strategy for the synthesis of less researched α-(hydroxyamino)diarylphosphine oxides has been developed and their antitumor activities are explored. Under water as a solvent and catalyst-free conditions, the addition of nitrones and diphenylphosphine oxide occurs smoothly to afford α-(hydroxyamino) diarylphosphine oxides in high yields. This reaction features a wide substrate scope, facile starting materials, atom economy, and easy purification. Moreover, the biological evaluation revealed that two synthesized derivatives 5e and 5f could serve as interesting anti-cancer agents for further development.

Regiocontrol by Halogen Substituent on Arynes: Generation of 3-Haloarynes and Their Synthetic Reactions

The use of arynes as highly reactive intermediates has attracted substantial attention in organic synthesis. To enhance the utility of arynes, the regiocontrol in the reactions of unsymmetrically substituted arynes is an important task. The introduction of halogen substituent at 3-position of arynes leads to sufficient regiocontrol for various synthetic reactions. This short review highlights the utility of 3-halo­arynes in organic synthesis and discusses the distortion models used to explain regioselectivity, representative reactions of 3-haloarynes generated from polyhaloarenes, and the preparation and reactions of easily activatable aryne precursors.

1 Introduction

2 Distortion Models

3 Reaction of Precursors Activated by an Organometallic Reagent or Base

4 Preparation of Easily Activatable Precursors

5 Reactions of Easily Activatable Precursors

6 Concluding Remarks

Recent Advances in Construction of C(sp2)–O Bonds via Aryne Participated Multicomponent Coupling Reactions

Aryne chemistry is a powerful synthetic technique that forms new bonds to aromatic rings. The recent resurgence of aryne-based multicomponent coupling strategies has led to an influx of methodologies for the mild synthesis of arene derivatives. In particular, these innovative discoveries broaden and streamline approaches toward phenol ether motifs, which are a prevalent structural component across a broad range of chemistry related research fields. Herein, this review aims to provide a comprehensive overview of the recent progress in the construction of C(sp2)–O bonds via aryne-induced multicomponent reactions. Special attention has been paid to reaction design and mechanistic pathways.

1 Introduction

2 Insertion-Based MCRs

3 Nucleophilic-Addition-Based MCRs

4 Cycloaddition-Based MCRs

5 Summary