Organocatalytic Multiple Cascade Reactions: A New Strategy for the Construction of Enantioenriched Tetrahydrocarbazoles

Synthesis of tetrahydrocarbazoles through a radical cation [4+2] cycloaddition reaction of 2-vinylindoles

A redox umpolung strategy for the synthesis of complex tetrahydrocarbazoles is reported. The reaction involves a visible light promoted radical cation [4+2] cycloaddition between 2-vinylindoles and conjugated alkenes that proceeds with good yields and diastereoselectivity.

Synthesis of Chiral Polycyclic Tetrahydrocarbazoles by Enantioselective Aminocatalytic Double Activation of 2-Hydroxycinnamaldehydes with Dienals

An efficient aminocatalytic enantioselective double-activation strategy has been developed that combines several different aminocatalytic modes in a cascade process, such as iminium ion, vinylogous iminium ion, trienamine, and dienamine activations. By using this strategy, 2-hydroxycinnamaldehydes worked well with various dienals via [4 + 2] cycloaddition and the oxa-Michael reaction-initiated cascade, respectively, leading to chiral polycyclic tetrahydrocarbazole and chromane derivatives with excellent diastereo- and enantioselectivities.

Advances in organocatalytic asymmetric reactions of vinylindoles: powerful access to enantioenriched indole derivatives

This review summarizes advances in vinylindole-based organocatalytic asymmetric reactions since 2008 and includes the applications of some methodologies in the total synthesis of natural products, points out remaining challenges in this research area.

Efficiently diastereoselective synthesis of functionalized hydro-carbazoles by base-mediated tandem annulation of 1-(2-amino-aryl)prop-2-en-1-ones and sulfur ylide

The base-promoted [3 + 3]/[1 + 4] tandem reaction of tosyl-protected o-amino α,β-unsaturated ketones and crotonate-derived sulfur ylide is developed for efficiently diastereoselective synthesis of functionalized hydrocarbazoles.

Catalytic asymmetric synthesis of tetrahydrocarbazoles

This feature article summarises recent advances in catalytic asymmetric synthesis of THCs, with emphases on reaction type and reaction mechanism.

Organocatalytic asymmetric synthesis of tetrahydrocarbazoles via an inverse-electron-demand Diels–Alder reaction of 2,3-indole-dienes with enals

A novel 2,3-indole-diene synthon was designed and first applied to an inverse-electron-demand Diels–Alder reaction to construct tetrahydrocarbazoles with excellent stereoselectivities.

Carrying pieces of information in organocatalytic bytes: Semiopoiesis-A new theory of life and its origins

Living beings have been classically described as autopoietic machines: chemical systems, which maintain a reproducible steady state by producing their components and boundaries. On the other hand, very simple autopoietic micelles have been produced in laboratory. They consist in micelles able to catalyse the production of their own surfactants. However is very clear that these autopoietic systems are unable to evolve. In this way, these autopoietic micelles cannot be associated to living organisms, which are always linked by evolutionary relationships. Here I claim that living beings are a class of autopoietic systems able to conserve molecular information, a feature denoted by the term semiopoiesis. By defining the molecular information of their products, semiopoietic systems control their interaction with the medium and, by being able to convey molecular information beneficial to the maintenance of the organization to their offspring, semiopoietic systems can evolve by natural selection. Information can be described as a specific state or order assumed among a set of other possible states or orders. Thus, molecular information is the specific order by which the molecular components are ordered, such as the sequence of nucleotides in nucleic acids or of amino acids in proteins. However, molecular information is not limited to copolymers. The atoms in small organic compounds may also present diverse orders, giving rise to isomers. Different isomers can present very distinct chemical and physical properties such that the biophysical-chemical properties of an organic compound are determined by its composition and molecular information i.e. the specific positions in which their atoms are posited. This molecular information can be conserved during reactions catalysed by selective organocatalysts. In this way, organocatalysts appear as plausible candidates to primitive hosts for the genetic information, before the emergence of systems based in biopolymers. The bases of a putative organocatalysts-based evolution are discussed. Finally, I argue that organocatalytic micelles can be designed to produce programmable materials, artificial photosynthesis, self-building materials and artificial life with relevant industrial impact.

Diastereo- and enantioselective construction of biologically important pyrrolo[1,2-a]indole scaffolds via catalytic asymmetric [3 + 2] cyclodimerizations of 3-alkyl-2-vinylindoles

A catalytic asymmetric [3 + 2] cyclodimerization of 3-alkyl-2-vinylindoles has been established, which efficiently constructed a pyrrolo[1,2-a]indole scaffold in a diastereo- and enantioselective fashion.

Highly enantioselective construction of carbazole derivatives via [4+2] cycloaddition of silyloxyvinylindoles and β,γ-unsaturated α-ketoesters

A highly enantioselective [4+2] cycloaddition between silyloxyvinylindoles and β,γ-unsaturated α-ketoesters was realized by an avaliable chiral N,N′-dioxide/yttrium triflate complex.

Strategies for the asymmetric functionalization of indoles: an update

During the past four years, the research of new synthetic methodologies for the rapid construction of enantiomerically pure substituted indole has had a fruitful and important growth.

The asymmetric Cu(ii)–indolinylmethanol complex catalyzed Diels–Alder reaction of 2-vinylindoles with β,γ-unsaturated α-ketoesters: an efficient route to functionalized tetrahydrocarbazoles

An efficient asymmetric Diels–Alder reaction of 2-vinylindoles with β,γ-unsaturated α-ketoesters for the synthesis of functionalized tetrahydrocarbazoles.