Copper(II)- and palladium(II)-catalyzed enantioselective Claisen rearrangement of allyloxy- and propargyloxy-indoles to quaternary oxindoles and spirocyclic lactones.

In this Article, a strategy to obtain highly enantioselective catalysts for the Claisen rearrangement of allyloxy- and propargyloxy-indoles is outlined. Ultimately, copper BOX and palladium BINAP or PHOX catalysts were discovered as superior in catalyzing Claisen rearrangements of allyloxy- or proparyloxy-substituted indoles to generate oxindoles bearing allyl- or allenyl-substituted quaternary centers. This method proved to be tolerant of a broad range of functional groups.

Total synthesis of chiral biaryl natural products by asymmetric biaryl coupling.

This tutorial review highlights the use of catalytic asymmetric 2-naphthol couplings in total synthesis. The types of chirality, chiral biaryl natural products, prior approaches to chiral biaryl natural products, and other catalytic asymmetric biaryl couplings are outlined. The three main categories of chiral catalysts for 2-naphthol coupling (Cu, V, Fe) are described with discussion of their limitations and advantages.

Design of a bisamidinium claisen rearrangement catalyst for monodentate substrates.

A bisamidinium catalyst has been designed for the Claisen rearrangement. The primary design feature is a dual hydrogen bonding array that can coordinate a singular oxygen atom of the substrate. The ability to function as a dual hydrogen donor is key as the bisamidinium accelerates the Claisen rearrangement to a greater extent than Brønsted acids with lower pK(a) values.

Catalytic enantioselective Meerwein-Eschenmoser Claisen rearrangement: asymmetric synthesis of allyl oxindoles.

The first catalytic, enantioselective Meerwein-Eschenmoser Claisen rearrangement has been achieved. Palladium(II) BINAP or phosphinooxazoline catalysts were employed to generate oxindole products with 100% conversion and up to 92% ee.