Boron-catalyzed dehydrative allylation of 1,3-diketones and β-ketone esters with 1,3-diarylallyl alcohols in water

H2 O ⋅ B(C6 F5 )3 -Catalyzed para-Alkylation of Anilines with Alkenes Applied to Late-Stage Functionalization of Non-Steroidal Anti-Inflammatory Drugs

Anilines are core motifs in a variety of important molecules including medicines, materials and agrochemicals. We report a straightforward procedure that allows access to new chemical space of anilines via their para-C-H alkylation. The method utilizes commercially available catalytic H2 O ⋅ B(C6 F5 )3 and is highly selective for para-C-alkylation (over N-alkylation and ortho-C-alkylation) of anilines, with a wide scope in both the aniline substrates and alkene coupling partners. Readily available alkenes are used, and include new classes of alkene for the first time. The mild reaction conditions have allowed the procedure to be applied to the late-stage-functionalization of non-steroidal anti-inflammatory drugs (NSAIDs), including fenamic acids and diclofenac. The formed novel NSAID derivatives display improved anti-inflammatory properties over the parent NSAID structure.

B(C6F5)3-catalyzed oxidation of α-diazoesters using DMF and molecular oxygen as oxygen sources

A metal-free catalytic oxidation of α-diazoesters via a green environmental-friendly route was developed. The α-diazoesters were converted to α-ketoesters using DMF and molecular oxygen as oxygen sources and B(C₆F₅)₃ as the catalyst, without any additives. This protocol has a broad adaptability of substrates and good compatibility with a range of functional groups, and it offers new insight into reactions catalyzed by B(C₆F₅)₃.

Selective Synthesis of Ketones and Chiral Allylic Alcohols from the Addition of Arylboronic Acids to α,β-Unsaturated Aldehydes Mediated by a Transition Metal/Monophosphorus Ligand System

Here, we demonstrated a transition metal-mediated/monophosphorus ligand system for the selective synthesis of ketones or chiral allylic alcohols in high yields/enantiomeric excess from the 1,2-addition of arylboronic acids to α,β-unsaturated aldehydes. Notably, isomerization of the chiral allylic alcohols to ketones was suppressed by the Ru-catalyzed/monophosphorus ligand system. The asymmetric catalytic system provides an alternative and efficient method of preparing chiral allylic alcohols.

Green protocols for Tsuji–Trost allylation: an overview

Since its inception in 1960s, the Tsuji–Trost reaction, an allylic substitution reaction with diverse nucleophiles such as phenols, amines, thiols, and active methylene compounds, has remained as one of the most useful and widely used organic reactions for the construction of C–C and C–heteroatom bonds. Allylic compounds such as allylic acetates, alcohols, halides, and carbonates undergo this transformation which plays an important role in the total synthesis of various natural products. The competence to incorporate synthetically demanding allylic functionalities makes it a beneficial tool for the synthesis of complex molecules. Over the last two decades, major advancements for this unique and facile Tsuji–Trost allylation reaction have been made with special emphasis to develop greener and sustainable protocols. This chapter presents an update on the significant progress focusing on the newly designed catalytic systems with high efficiency, the use of eco-friendly solvents or solvent-free conditions, low or room temperature conditions and waste management, along with future outlook.