Palladium-catalyzed preparation of Weinreb amides from boronic acids and N-methyl-N-methoxycarbamoyl chloride

Accessing 1,8-Naphthyridone-3-carboxylic Acid Derivatives and Application to the Synthesis of Amfonelic Acid

1,8-Naphthyridone-3-carboxyl is the core structure of several on-market antibacterial drugs. It has prompted significant interest from the synthetic community. Here, we report a practical synthesis of diversely functionalized 1,8-naphthyridone-3-carboxylic acid derivatives starting from readily available and inexpensive nicotinic acid derivatives. All key steps have been optimized. Furthermore, the usefulness of this protocol has been exemplified by the first synthesis of amfonelic acid.

Indolylboronic Acids: Preparation and Applications

Indole derivatives are associated with a variety of both biological activities and applications in the field of material chemistry. A number of different strategies for synthesizing substituted indoles by means of the reactions of indolylboronic acids with electrophilic compounds are considered the methods of choice for modifying indoles because indolylboronic acids are easily available, stable, non-toxic and new reactions using indolylboronic acids have been described in the literature. Thus, the aim of this review is to summarize the methods available for the preparation of indolylboronic acids as well as their chemical transformations. The review covers the period 2010-2019.

Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides

A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp²)-H functionalization of benzyl nitriles in the presence of activated C(sp³)-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.

Suzuki-miyaura cross-coupling in acylation reactions, scope and recent developments

Since the first report and due to its handiness and wide scope, the Suzuki-Miyaura (SM) cross coupling reaction has become a routine methodology in many laboratories worldwide. With respect to other common transition metal catalyzed cross couplings, the SM reaction has been so far less exploited as a tool to introduce an acyl function into a specific substrate. In this review, the various approaches found in the literature will be considered, starting from the direct SM acylative coupling to the recent developments of cross coupling between boronates and acyl chlorides or anhydrides. Special attention will be dedicated to the use of masked acyl boronates, alkoxy styryl and alkoxy dienyl boronates as coupling partners. A final section will be then focused on the acyl SM reaction as key synthetic step in the framework of natural products synthesis.