Nucleophilic H-Phosphites, H-Phosphinates, and H-Phosphine Oxides in Organic Reactions

P(O)–H compounds like H-phosphites, H-phosphinates, and H-phosphine oxides are widely used as nucleophiles. Herein, their reactions with unsaturated compounds, C–H activation, the Hirao reaction, P–C, P–S, P–O, P–N, and P–F couplings are thoroughly discussed and summarized. This review will focus on their reactions with alkenes, alkynes, enamides, propynoic acids, epoxide, arynes, arenes, quinones, isothiocyanates, diazo compounds, aldehydes, ketones, imines, pyridines, acid derivatives, carbocations, aryl halides, dibromoalkenes, disulfides, thiosulfates, sulfonyl chlorides, iodonium salts, amines, alcohols, and thiols.

1 Introduction

2 Addition to Alkenes/Alkynes

3 Addition to Other Unsaturated Compounds

4 Coupling with Carbocations

5 Phosphorylation of Aryl C–H Bonds

6 Hirao Reaction

7 P–S, P–O, P–N, or P–F Coupling

8 Conclusions

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

The allene functionality has participated in one of the most exciting voyages in organic chemistry, from chemical curiosities to a recurring building block in modern organic chemistry. In the last decades, a special kind of allene, namely, allenol, has emerged. Allenols, formed by an allene moiety and a hydroxyl functional group with diverse connectivity, have become common building blocks for the synthesis of a wide range of structures and frequent motif in naturally occurring systems. The synergistic effect of the allene and hydroxyl functional groups enables allenols to be considered as a unique and sole functionality exhibiting a special reactivity. This Review summarizes the most significant contributions to the chemistry of allenols that appeared during the past decade, with emphasis on their synthesis, reactivity, and occurrence in natural products.

Three-Component Reactions of α-Amino Acids, p-Quinone Monoacetals, and Diarylphosphine Oxides to Selectively Afford 3-(Diarylphosphinyl)anilides and N-Aryl-2-diarylphosphinylpyrrolidines

The three-component reactions of α-amino acids, p-quinone monoacetals (or p-quinol ethers), and diarylphosphine oxides have been developed for the synthesis of 3-(diarylphosphinyl) anilides and N-aryl-2-diarylphosphinylpyrrolidines. The transformations may involve the in situ generation of conjugated azomethine ylides or 2-azaallyl anion species from the reaction of α-amino acids and p-quinone monoacetals, which are further trapped by diarylphosphine oxides.

Cu-Catalyzed Synthesis of Tetrasubstituted 2,3-Allenols through Decarboxylative Silylation of Alkyne-Substituted Cyclic Carbonates

An efficient and mild Cu-catalyzed protocol has been developed for the decarboxylative silylation of alkyne-functionalized cyclic carbonate substrates affording 2,3-allenols featuring four different substituents. This practical methodology gives access to a wide scope of tetrasubstituted functionalized allenes in excellent yields.

Zinc-catalyzed regioselective C–P coupling of p-quinol ethers with secondary phosphine oxides to afford 2-phosphinylphenols

A highly regioselective C–P coupling reaction of p-quinol ethers with secondary phosphine oxides is developed as a new synthesis method for 2-phosphinylphenols by using Zn(OTf)₂ as the catalyst.

Copper-catalyzed silylation reactions of propargyl epoxides: easy access to 2,3-allenols and stereodefined alkenes

Efficient silylation reactions of propargyl epoxides catalyzed by copper catalysts have been developed.