2.4 Trofimov Synthesis of Pyrroles.

A one pot synthesis of pyrroles and N-vinylpyrroles from ketones and acetylenes (via the ketoximes) in a KOH–DMSO superbase system (the Trofimov reaction [1-3]) is used ever more widely thanks to its simplicity and the availability of the starting materials.

Mechanism of pyrrole synthesis from ketoximes and acetylene.

Mechanism of pyrrole synthesis from ketoximes and acetylene
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Trofimov Pyrrole Synthesis functionalized by directed ..

Various dl- and meso-tetraarylethanes were diastereoseletively synthesized by this new protocol, where base plays the role of the principle modulator: Grignard reagents selectively provide the C2 isomers, whereas KOt-Bu promotes the formation of the meso-tetraarylethanes.

Pyrrole synthesis - Organic chemistry

Dendralenes are cross-conjugated hydrocarbons that quickly became attractive starting materials for organic synthesis. The following example shows a diene-transmissive Diels–Alder addition of DMAD to dendralene . The process could be stopped at the mono adduct stage , but it could also be performed, under harsher conditions, to yield directly the 2:1 adduct (Scheme []).[]

In addition, this protocol demonstrates the ...This study brings new insights into the synthetic scope and mechanism of the reaction.
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2016-10-31 · A Paperback edition by Boris A

DMAD is often used in natural product synthesis in key transformation steps. A recent example presenting a stereo­selective synthesis of marine sesterterpenes and included a Diels–Alder addition with DMAD (Scheme []).[]

2016-11-16 · Chemistry of Pyrroles

(2002) Design and synthesis of pyrrolidine-5,5-trans-lactams (5-oxohexahydropyrrolo[3,2-]pyrroles) as novel mechanism-based inhibitors of human cytomegalovirus protease.

Découvrez et achetez Chemistry of Pyrroles

Zwitterions are transient intermediates formed by the addition of neutral nucleophiles to electrophilic receptors. Zwitterions are a unique tool in organic synthesis leading to a variety of heterocycles. These reactive intermediates can be captured by suitable substrates (e.g., nucleophiles), after a series of transformations. In fact, it was found that in the case of acetylenedicarboxylate, three reaction paths are possible (paths A, B and C). Basically, in both paths A and C the nucleophile is added irreversibly, leading to a multi-component reaction. On the other hand, in path B the nucleophile gets eliminated from the system, and thus plays a catalytic role, conducting a two-component reaction. Path B usually involves nucleophiles, such as phosphines and tertiary amines such as pyridines and quinolines, while paths A and C involve mainly nucleophilic heterocyclic carbenes (NHCs) and isocyanides (Scheme []).

2016-11-16 · By Boris A

Each section includes a description of the reaction, the historical perspective, a mechanism for the reaction, variations and improvements on the reaction, synthetic utilities of the reaction, experimental details, and references to the current primary literature.