Jiaqiang Li

Umpolung Strategy for Synthesis of β-Ketonitriles through Hypervalent Iodine-Promoted Cyanation of Silyl Enol Ethers

An efficient method to synthesize β-ketonitriles from silyl enol ethers by an umploung hypervalent iodine(III)-CN species generated in situ from PhIO/BF3·Et2O/TMSCN has been developed for the first time. This method can be applied to structurally diverse aromatic and aliphatic substrates and further extended to preparation of bioactive compounds like 5-aminopyrazole and 5-aminoisoxazole.

Architecture of β-Graphdiyne-Containing Thin Film Using Modified Glaser–Hay Coupling Reaction for Enhanced Photocatalytic Property of TiO2

β-Graphdiyne (β-GDY) is a member of 2D graphyne family with zero band gap, and is a promising material with potential applications in energy storage, organic electronics, etc. However, the synthesis of β-GDY has not been realized yet, and the measurement of its intrinsic properties remains elusive. In this work, β-GDY-containing thin film is successfully synthesized on copper foil using modified Glaser-Hay coupling reaction with tetraethynylethene as precursor. The as-grown carbon film has a smooth surface and is continuous and uniform. Electrical measurements reveal the conductivity of 3.47 × 10-6 S m-1 and the work function of 5.22 eV. TiO2 @β-GDY nanocomposite is then prepared and presented with an enhancement of photocatalytic ability compared to pure TiO2 .

Superacid BF3–H2O promoted benzylation of arenes with benzyl alcohols and acetates initiated by trace water

A convenient procedure employing simple starting materials benzyl alcohols and acetates as the benzyl donors to assemble a series of diarylalkanes through benzylation of arenes using in situ prepared superacid BF3–H2O as an efficient promoter has been developed. The beneficial role of water in the reaction has been clarified with combination of control experiments and 11B NMR analysis. This reaction is a self-promoted model, which is triggered by the trace of water and continuously promoted by self released by-product water (or carboxylic acid). A wide range of substrates are investigated and the moderate to excellent yields and the good regioselectivities for secondary benzyl alcohols as well as arenes bearing electron-withdrawing groups have been achieved. As a result, moisture in the reaction system has been utilized as an efficient initiator in all benzylation cases.

Ethers as hydrogen sources in BF3·OEt2 promoted reduction of diphenylmethyl alcohols, ethers and esters to hydrocarbons

A novel ether/BF3 reductive system has been described, in which diphenylmethanols and their ether and ester derivatives are used as starting materials. Reductions are performed in ether under reflux and an argon atmosphere, and the addition of extra water is beneficial to this reduction. A series of alkanes are able to be prepared with good to excellent yields. A deuterated experiment exhibits that the reductive hydrogen is generated from ether. The mechanism is discussed in detail to explain the observed reactivity.

Template Synthesis of an Ultrathin β-Graphdiyne-Like Film Using the Eglinton Coupling Reaction

β-Graphdiyne (β-GDY) is a two-dimensional carbon material with zero band gap and highly intrinsic carrier mobility and a promising material with potential applications in electronic devices. However, the synthesis of continuous single or ultrathin β-GDY has not been realized yet. Here, we proposed an approach for ultrathin β-GDY-like film synthesis using graphene as a template because of the strong π-π interaction between β-GDY and graphene. The as-synthesized film presents smooth and continuous morphology and has good crystallinity. Electrical measurement reveals that the film presented a conductivity of 1.30 × 10-2 S·m-1 by fabricating electronic devices on β-GDY grown on a dielectric hexagonal boron nitride template.