There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Isolation and synthesis of biologically active carbazole alkaloids

Schiff bases: A short review of their antimicrobial activities

Spirooxindoles have become a privileged skeleton given their broad and promising activities in various therapeutic areas. The strategies and catalyst systems described here highlight recent advances in the enantioselective synthesis of spirooxindoles via organocascade strategies. Various organocatalysts with distinct activation modes have found application in constructing these sophisticated compounds. This review focuses on the enantioselective synthesis of spirooxindoles via organocascade strategies and is organized on the basis of three primary starting materials and then further subdivided according to the types of organocatalyst. These methods are of importance for the synthesis of complex natural products and the design of new pharmaceutical compounds. We believe that compounds based on spirooxindole skeletons have the potential to provide novel therapeutic agents and useful biological tools.

https://www.scripps.edu/barbas/pdf/ChengACSCatal2014.pdf

Organocatalytic Asymmetric Assembly Reactions: Synthesis of Spirooxindoles via Organocascade Strategies

Indoles in multicomponent processes (MCPs).

In recent years, organocatalysis has enhanced its importance as a tool for the synthesis of enantiomerically enriched compounds. Among the candidates for organocatalysis, the construction of asymmetric quaternary carbons is regarded as a challenging problem in organic synthesis. In particular, 3,3′-disubstituted oxindoles have one or more asymmetric quaternary carbon atoms and they represent a large family of bioactive compounds and synthetic derivatives that mimicry natural products. Therefore they are good targets for drug candidates and in the last two years many papers have appeared on organocatalytic methods for the synthesis of 3,3′-disubstituted oxindoles. Moreover, in the last few years 2-substituted and 2,2′-disubtituted 3-indolinones have also attracted the interest of chemists. This review aims to cover the literature on these topics from its origin to the end of 2011.

Recent advances in organocatalytic methods for the synthesis of disubstituted 2- and 3-indolinones

The desire for new synthetic methodologies for the rapid construction of enantiomerically pure substituted indole has been a fruitful driving force for chemical research in the last few years. This research line has produced a stunning array of enantioselective technologies either metal or organocatalyzed. This critical review documents the development of organocatalytic indole alkylation strategies, until the end of 2009 (127 references).

Organocatalytic strategies for the asymmetric functionalization of indoles

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 This research line continues to produce stunning arrays of enantioselective technologies either metal or organocatalyzed Thus, an update of our previous review (Chem Soc Rev, 2010, 39, 4449–4465) has become necessary and this critical review documents the literature on this topic, until the end of 2013

Strategies for the asymmetric functionalization of indoles: an update.

The reaction of vinyl grignard reagents with 2-substituted nitroarenes: A new approach to the synthesis of 7-substituted indoles

In 1989, the reaction of vinyl magnesium halides with ortho-substituted nitroarenes leading to indoles was discovered. This reaction is now frequently reported as the “Bartoli reaction” or the “Bartoli indole synthesis” (BIS). It has rapidly become the shortest and most flexible route to 7-substituted indoles, because the classical indole syntheses generally fail in their preparation. The flexibility of the Bartoli reaction is great as it can be extended to heteroaromatic nitro derivatives and can be run on solid support. This review will focus on the use of the Bartoli indole synthesis as the key step in preparations of complex indoles, which appeared in the literature in the last few years.

Renato Dalpozzo

Papers

Recent advances in organocatalytic methods for the synthesis of disubstituted 2- and 3-indolinones

Organocatalytic strategies for the asymmetric functionalization of indoles

Strategies for the asymmetric functionalization of indoles: an update.

The reaction of vinyl grignard reagents with 2-substituted nitroarenes: A new approach to the synthesis of 7-substituted indoles

Applications of Bartoli indole synthesis