Current Organocatalysis (v.2, #2)

Meet the Editor in Chief: by Bimal K. Banik (77-77).

Editorial (Thematic Issue: Advances in Organocatalytic Chemistry) by Jose Ramon Suarez, Isabel Garcia Alvarez (78-78).

Organocatalysis Chemistry in Flow by Alessandra Puglisi, Maurizio Benaglia, Riccardo Porta, Francesca Coccia (79-101).
The last decade has witnessed a huge growth in the use of flow chemistry as wellestablished procedure for performing chemical transformations; indeed, under continuous flow conditions, more sustainable, safer and easier scalable processes could be developed with respect to conventional batch procedures.
Organocatalysis has recently become an effective methodology for performing stereoselective reactions in continuo: metal-free catalytic processes could ensure high levels of enantioselectivity avoiding the contamination of final products with potentially toxic metal species. Since many academic research groups are focusing their efforts in this field, in the near future stereoselective catalytic flow processes could found a practical application in the manufacturing of Active Pharmaceutical Ingredients and chiral intermediates.
In the present review most recent examples of continuous flow processes employing organic molecules as catalysts will be discussed. A particular attention will be devoted to stereoselective reactions promoted by chiral organocatalysts under continuous flow conditions. Moreover, the great potential in combining flow stereoselective processes with solidsupported catalysis in catalytic reactors as well as with photoredox catalysis will be highlighted.

Pursuing Chemical Efficiency by Using Supported Organocatalysts for Asymmetric Reactions under Aqueous Conditions by Gabriela Guillena, Diego Alonso, Alejandro Baeza, Rafael Chinchilla, Jesus Flores-Ferrandiz, Melania Gomez-Martinez, Paz Trillo (102-123).
Over the past decade, a great effort has been made by the chemical community to improve the efficiency of organic transformations and allow sustainable processes. Merging the use of supported and recyclable organocatalysts and aqueous conditions for the asymmetric synthesis of valuable molecules, has led to outstanding contributions in the area of green chemistry. Recent progresses in the field include the implementation of these methodologies in the large scale production of chiral molecules using automated flow chemistry.

The use of organocatalysis has simplified and increased the potential of synthetic approaches to natural products. Different aspects, regarding applications and even perspectives of iminium- or enamine-catalysis have been studied in this increasingly developing area during the past decades. Addressing those features, this article aims to give an overview through selected examples, focusing on discussing academic insights of a variety of key reactions such as aldol and Mannich reactions, and 1,4-conjugated additions, as well as applications to the synthesis of natural products, in the period 2012-to date.

Recent Applications of Ionic Liquids in Organocatalytic Processes by Bernardo Herradon, Enrique Mann (150-170).
In this review, we report an overview of some recent applications of ionic liquids in diverse organocatalyzed transformations such as, for example, the conjugate addition, Diels Alder and the aldol type reactions. Examples of ionic liquids acting both as catalyst ('nonsolvent applications') and as reaction media are described. The interesting potential applications resulting of the merging of two such active research areas as ionic liquids and organocatalysis are only just starting to be explored by the synthetic organic chemists.

Organocatalytic Oxidation Reactions by Dimitris Limnios, Christoforos G. Kokotos (171-190).
The area of Organocatalysis has flourished during the last 15 years. However, the area of organocatalytic oxidations has received less attention. In this review article, recent advances in the area of organocatalytic oxidations is presented. In more detail, organocatalytic approaches for the epoxidation reaction of alkenes, organocatalytic oxidation of sulfides, tertiary amines and azines and silanes will be presented.

Pyrrolidine Based Trifluro Organocatalyst: A Trap for syn Isomer of Functionalized Piperidines by Prashant B. Thorat, Santosh V. Goswami, Manohar V. Lokhande, Sudhakar R Bhusare (191-202).
The pyrrolidine trifluoro based organocatalyst has been found to be an efficient catalyst for the synthesis of syn and anti isomer of highly substituted piperidines. The trifluorine is used to trap syn isomer of functionalized piperidines. The one-pot synthesis via multi-component reaction of methylacetoacetate, aromatic aldehydes and various amines in ethanol at 80A°C condition to afford pure anti product in excellent yield and pure syn isomer at lower temperature in some cases with moderate yield of products. At room temperature the product was obtained as syn:anti mixture with anti isomer as dominant in almost all cases.

This paper describes the synthesis, characterization and catalytic activities of three closed-loop picolinamide complexes. They were prepared by Mn(II), Cu(II), Co(II) acetate and macrocylic ligand (L), which was formed by the condensation between 2,6-pyridinedicarboxylic acid chloride and 2,6-diaminopyridine. These complexes have been characterized by XRD, 1H NMR, IR, UV-vis DRS, Element analysis and TGA. Their catalytic activities in allylic oxidation of cyclohexene and isophorone with molecular oxygen as primary terminal oxidant were investigated for the first time. The influences of reaction temperature, the amount of catalyst and reaction time on the oxidation of cyclohexene by Co-L were also investigated. The results show that the Co-L can be obtained optimum catalytic efficiency, giving 58.2% conversion of cyclohexene and maximum selectivity of 83.4% for 2-cyclohexene-1-one; 15.4% conversion of isophorone and 46.2% selectivity of ketoisophorone. The heterogeneous catalysts can be easily separated for reuse at least three times without any significant change in selectivity.