Transition metal-promoted biomimetic steps in total syntheses

Abstract

This review summarizes the state-of-the-art on the use of transition metals in synthetic steps inspired by biosynthesis. After an introduction showing the importance of metals in life processes, with special emphasis on biosynthetic processes, their place in biomimetic synthesis will be described. Topics include oxidative cyclizations for polyether synthesis, electrophilic and radical cyclizations of polyprenoids, the role of palladium in electrocyclizations, oxidative biaryl couplings and other rearrangement steps.

The mechanism(s) of action of antioxidants: From scavenging reactive oxygen/nitrogen species to redox signaling and the generation of bioactive secondary metabolites

“…A common feature of these types of reactions is that the oxidizing agent is an activated (ie reactive) oxygen or nitrogen species formed by electron transfer from the transition metal, aiming to mimic the way oxidase enzymes work. 152,153 Accordingly, it is unsurprising that biomimetic approaches are extensively used in the total synthesis of natural products, 154 including various functionalization or cross-coupling reactions of phenolic/polyphenolic compounds. [155][156][157] Nevertheless, more than providing a remarkable toolkit for solving synthetic chemical challenges, biomimetic oxidative chemistry also offers a platform to study the oxidative metabolism of drugs.…”

Stereoselectivity and nonmigratory insertion mechanism of dimethylacetylene dicarboxylate into metallocene‐hydride of Cp2M(L)H [Cp =η5‐C5H5; M = Nb, V; L = CO, P (OMe)3]: A DFT study

“…The unique properties of first‐row transition metals, especially their generally reduced electronegativity, offer orthogonal opportunities for reaction development relative to their second‐ and third‐row counterparts. However, their remarkable ability to construct varied molecular structures using these metals suggests underutilized potential for first‐row transition chemistry …”

“…However, their S C H E M E 1 Proposed mechanism for the process of E-isomer formation S C H E M E 2 Proposed mechanism for the process of Z-isomer formation remarkable ability to construct varied molecular structures using these metals suggests underutilized potential for first-row transition chemistry. [34,35] In this paper, the mechanism of the insertion reaction between Cp 2 Nb(CO)H (Cp = η 5 -C 5 H 5 ) and dimethylacetylene dicarboxylate (DMAD) has been investigated based on quantum calculations. The conversion from (Z)-alkenyl to (E)-alkenyl is explored in detail.…”

Rapid Synthesis of Polyprenylated Acylphloroglucinol Analogs via Dearomative Conjunctive Allylic Annulation

“…2 Such an approach to PPAP core structures would take advantage of biosynthetic, innate reactivity 8,9 (phloroglucinol dearomatization, allylic alkylation) and utilize the predictably reactive reagent 2 which has been utilized extensively in conjunctive bond-forming processes. 10 Herein, we report our initial discoveries enabling the rapid construction of diverse PPAP analogs for biological evaluation through this modular and step-economic sequence.…”