Metal-catalysed C–H bond functionalisation has had a significant impact on how chemists make molecules. Translating the methodological developments to their use in the assembly of complex natural products is an important challenge for the continued advancement of chemical synthesis. In this tutorial review, we describe selected recent examples of how the metal-catalysed C–H bond functionalisation has been able to positively affect the synthesis of natural products.

Recent developments in natural product synthesis using metal-catalysed C–H bond functionalisation

Occurrence, Biogenesis, and Synthesis of Biologically Active Carbazole Alkaloids

https://chemistry.mdma.ch/hiveboard/rhodium/pdf/piper.phytochemistry.pdf

Phytochemistry of the genus Piper

Tubulin is the biochemical target for several clinically used anticancer drugs, including paclitaxel and the vinca alkaloids vincristine and vinblastine. This review describes both the natural and synthetic agents which are known to interact with tubulin. Syntheses of the more complex agents are referenced and the potential clinical use of the compounds is discussed. This review describes the biochemistry of tubulin, microtubules, and the mitotic spindle. The agents are discussed in relation to the type of binding site on the protein with which they interact. These are the colchicine, vinca alkaloid, rhizoxin/maytansine, and tubulin sulfhydryl binding sites. Also included are the agents which either bind at other sites or unknown sites on tubulin. The literature is reviewed up to October 1997. © 1998 John Wiley & Sons, Inc., Med Res Rev, 18, No. 4, 259–296, 1998.

Tubulin as a target for anticancer drugs: agents which interact with the mitotic spindle.

The recent advent of transition-metal mediated CH activation is revolutionizing the synthetic field and gradually infusing a “CH activation mind-set” in both students and practitioners of organic synthesis. As a powerful testament of this emerging synthetic tool, applications of CH activation in the context of total synthesis of complex natural products are beginning to blossom. Herein, recently completed total syntheses showcasing creative and ingenious incorporation of CH activation as a strategic manoeuver are compared with their “non-CH activation” counterparts, illuminating a new paradigm in strategic synthetic design.

C-H activation: a complementary tool in the total synthesis of complex natural products.

Studies on cycloadditions of C,N-diarylnitrones to cinnamic acid amides were carried out. The diastereoisomeric (I, II) and (in some cases) regioisomeric (III) cycloadducts obtained were characterized by spectroscopic and X-ray data. Conformational studies were carried out by molecular modelling.

1,3-Dipolar Cycloadditions VI (1). Structure and Conformation of Cycloadducts from Reactions of C-Aryl-N-phenylnitrones with Substituted Cinnamic Acid Amides

The gum resin of Ferula assafoetida Linn. afforded one new sesquiterpene, asimafoetida 1 and three known sesquiterpenoid coumarins. The structure has been established from extensive 2D NMR spectral studies as 7'-[7-(1R,3S)-5-Hydroxy-6,6-dimethyl-2-methylene-cyclohexyl]-9-methyl-9-pentenyl]oxy]-2H-1-benzopyran-2-one. The other three known compounds are ferulic acid, farnesiferol A and farnesiferol C.

https://journals.sagepub.com/doi/pdf/10.1177/1934578X0900400801

A new sesquiterpenoid coumarin from Ferula assafoetida.

A new alkamide from Piper sylvaticum

The first report of unusual flipping of the cycloadducts from 1,3-dipolar cycloaddition of 3,4,5,6-tetrahydropyridine N-oxide to N-cinnamoyl piperidines

13C NMR spectra of six kawa-pyrones (styryl α-pyrones) have been assigned. The assignments are based on the splitting pattern in the coupled spectra, comparison of the chemical shifts with those of model compounds and by application of additivity relationships. The 13C NMR of styrene was also reinvestigated.

Avijit Banerji

Papers

1,3-Dipolar Cycloadditions VI (1). Structure and Conformation of Cycloadducts from Reactions of C-Aryl-N-phenylnitrones with Substituted Cinnamic Acid Amides

A new sesquiterpenoid coumarin from Ferula assafoetida.

A new alkamide from Piper sylvaticum

The first report of unusual flipping of the cycloadducts from 1,3-dipolar cycloaddition of 3,4,5,6-tetrahydropyridine N-oxide to N-cinnamoyl piperidines

Carbon‐13 NMR spectroscopy of kawa‐pyrones