Solvent-Free Mizoroki-Heck Reaction Applied to the Synthesis of Abscisic Acid and Some Derivatives

Palladium-Catalyzed Aerobic α,β-Dehydrogenation of Aliphatic Amides

A Pd(II)-catalyzed α,β-dehydrogenation of substituted aliphatic amides assisted by a reusable bis-chelating 8-aminoquinoline ligand is demonstrated. Broad spectra of β-substituted including olefin-substituted aliphatic amides are well tolerated. The present protocol efficiently dehydrogenates the less acidic aliphatic amides via the chelation-assisted β-C-H bond activation and replaces the traditional enolate-based strategy.

Synthesis of Conjugated Dienes in Natural Compounds

This review describes the various synthetic methods commonly used to obtain molecules possessing conjugated dienes. We focus on methods involving cross-coupling reactions using various metals such as nickel, palladium, ruthenium, cobalt, cobalt/zinc, manganese, zirconium, or iron, mainly through examples that aimed to access natural molecules or their analogues. Among the natural molecules covered in this review, we discuss the total synthesis of a phytohormone, Acid Abscisic (ABA), carried out by our team involving the development of a conjugated diene chain.

Stereoselective Synthesis of 1,3,5-Trienes from Alkynones and Allyl Carbonyl Compounds Through C-C σ-Bond Cleavage under Transition-Metal-Free Conditions

An atom-economical transition-metal-free protocol for the stereoselective synthesis of conjugated trienes has been developed. These transformations were realized through base promoted C-C σ-bond cleavage reactions of allyl carbonyl compounds. This...

Cross-coupling reactions towards the synthesis of natural products

Cross-coupling reactions are powerful synthetic tools for the formation of remarkable building blocks of many naturally occurring molecules, polymers and biologically active compounds. These reactions have brought potent transformations in chemical and pharmaceutical disciplines. In this review, we have focused on the use of cross-coupling reactions such as Suzuki, Negishi, Heck, Sonogashira and Stille in the total synthesis of some natural products of recent years (2016-2020). A short introduction of mentioned cross-coupling reactions along with highlighted aspects of natural products has been stated in separate sections. Additionally, few examples of natural products via incorporation of more than one type of cross-coupling reaction have also been added to demonstrate the importance of these reactions in organic synthesis.

New Trends in C-C Cross-Coupling Reactions: The Use of Unconventional Conditions

The ever-growing interest in the cross-coupling reaction and its applications has increased exponentially in the last decade, owing to its efficiency and effectiveness. Transition metal-mediated cross-couplings reactions, such as Suzuki-Miyaura, Sonogashira, Heck, and others, are powerful tools for carbon-carbon bond formations and have become truly fundamental routes in catalysis, among other fields. Various greener strategies have emerged in recent years, given the widespread popularity of these important reactions. The present review comprises literature from 2015 onward covering the implementation of unconventional methodologies in carbon-carbon (C-C) cross-coupling reactions that embodies a variety of strategies, from the use of alternative energy sources to solvent- free and green media protocols.

Concise and Practical Total Synthesis of (+)-Abscisic Acid

(+)-Abscisic acid 1 was obtained in a concise total synthesis from ethyl 2,6,6-trimethyl-4-oxocyclohex-2-ene-1-carboxylate (2) with 41% overall yield in seven steps. A hydroxyl group was stereoselectively introduced by Sharpless asymmetric epoxidation; then, the side chain was appended with dimethyl 2-(propan-2-ylidene)malonate (7); subsequently, selective decarboxylation of diacid 8 established the Z-configuration of the conjugated acid 1.

Stereoselective synthesis of conjugated trienes via 1,4-palladium migration/Heck sequence

An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of conjugated trienes.

Catalyzed Mizoroki-Heck Reaction or C-H Activation

In the last few decade, research conducted on the development by catalytic processes of C-C bonds formation on the one hand and on the other hand on the activation of C-H bonds has grown considerably [...]