Impact of Design of Experiments in the optimisation of catalytic reactions in academia

Design of Experiments (DoE) is extensively and routinely used in industry; however, in the last decades, it has been gaining increasing interest in organic synthesis in academia. The use of Chemometrics is an attractive strategy to find the real optimum in chemical reactions, especially when affected by several variables. DoE has been applied in a growing number of synthetic transformations over the years, where it can undoubtedly help in the process optimisation, saving costs and time. This review concisely discusses the chemometric basis of Design of Experiments and highlights several examples in which DoE has been applied in organic synthesis. Table of contents 1 Introduction 2 Chemometric basis of DoE 3 DoE applied in catalysis: examples 4 Conclusions

The Rearrangement of Alkylallenes to 1,3-Dienes

1,3-Dienes are vital building blocks in organic synthesis. They underpin many fundamental synthetic transformations and are present in numerous natural products and drug candidate molecules. The rearrangement of an alkylallene to a 1,3-diene is an atom efficient, redox neutral, transformation that provides a straightforward synthetic route to functionalized 1,3-dienes. Herein, we provide an account of this transformation using allenes that are not predisposed by the presence of heteroatoms or electron-withdrawing groups directly attached to the allene. Early reports of this skeletal rearrangement are acid-mediated approaches, with limited substrate scope, but they provide valuable mechanistic insights. More recent transition metal-mediated approaches that exhibit improved substrate scope are described, together with isolated examples that have utilized this rearrangement.

Organophosphane-Catalyzed Construction of Functionalized 2-Ylideneoxindoles via Direct β-Acylation

We report an efficient method for the direct β-acylation of 2-ylideneoxindoles with acyl chlorides in the presence of base-catalyzed by organophosphanes. A variety of functionalized 2-ylideneoxindoles were prepared in moderate to good yields under metal-free and mild conditions via a tandem phospha-Michael/O-acylation/intramolecular cyclization/ rearrangement sequence. The mechanistic investigations revealed that the C-O bond cleavage on possible betaine intermediate is the key step for the installation of keto-functionality at β-position of 2-ylideneoxindoles in a highly stereospecific manner. The synthetic utility of this protocol could also be proven by scale-up reactions and synthetic transformations of the products.

Application of industrially relevant HFO gases in organic syntheses

Hydrofluoroolefin (HFO) gases are state-of-the-art cooling agents with widespread household and industrial applications. Considering their structural benefits these fluorous feedstocks gained attention of organic chemists in the last couple of years. In this short review we summarized the existing synthetic transformations of these gaseous starting material and present their applicability in the synthesis of fluorine containing organic molecules, which have potential importance as building blocks and reagents for diverse syntheses.

Synthetic Transformations and Medicinal Significance of 1,2,3-Thiadiazoles Derivatives: An Update

The 1,2,3-thiadiazole moiety occupies a significant and prominent position among privileged heterocyclic templates in the field of medicine, pharmacology and pharmaceutics due to its broad spectrum of biological activities. The 1,2,3-thiadiazole hybrid structures showed myriad biomedical activities such as antifungal, antiviral, insecticidal, antiamoebic, anticancer and plant activators, etc. In the present review, various synthetic transformations and approaches are highlighted to furnish 1,2,3-thiadiazole scaffolds along with different pharmaceutical and pharmacological activities by virtue of the presence of the 1,2,3-thiadiazole framework on the basis of structure–activity relationship (SAR). The discussion in this review article will attract the attention of synthetic and medicinal researchers to explore 1,2,3-thiadiazole structural motifs for future therapeutic agents.