Alternative methods for the MnO2 oxidation of codeine methyl ether to thebaine utilizing ionic liquids

Ionic Liquid-Like Pharmaceutical Ingredients and Applications of Ionic Liquids in Medicinal Chemistry: Development, Status and Prospects

Background:

As a new kind of green media and bioactive compounds with special structure, Ionic Liquids (ILs) are attracting much attention and applied widely in many fields. However, their roles and potential have not been fully recognized by many researchers of medicinal chemistry. Because of obvious differences from other traditional drugs and reagents, their uses and performance together with advantages and disadvantages need to be explored and reviewed in detail.

Methods:

For a systematic and explicit description of the relationship between ILs and medicinal chemistry, all of the contents were elucidated and summarized in a series of independent parts. In each part, it started from the research background or a conceptual framework and then specific examples were introduced to illustrate the theme. Finally, the important conclusions were drawn and its future was outlooked after the discussion about related key problems appearing in each mentioned research. Meanwhile, methodologies such as empirical analysis, comparison and induction were applied in different sections to exposit our subject.

Results:

The whole review was composed of five parts, and 148 papers were cited in total. Related basic information of ionic liquids was provided on the basis of representative references, including their concepts and important characters. Then 82 papers outlined ionic liquid-like active pharmaceutical ingredients, which unfolded with their major biological activities (antimicrobial activity, antibiofilm activity, antitumor activity, anticholinesterase activity and so on). Applications of ionic liquids in the synthesis of drugs and pharmaceutical intermediates were elaborated in 92 papers to illustrate the important roles of ILs and their extraordinary properties in this field. Moreover, new technologies (such as immobilization of IL, microwave reaction, solventfree synthesis, microreactor, etc) were introduced for further innovation. Finally, 26 papers were included to expound the status of the IL-assisted derivatization of various natural lead compounds.

Conclusion:

This review placed emphasis on chemical structures of ILs and their structureactivity relationships in a specific manner, leading to meaningful and valuable related information to some related fields and thus promotes further development and application of various ILs for medicinal chemistry. The deep exploration for key scientific problems is the driving force to propel their theoretical breakthrough and industrial production.

Ionic Liquids: The Neglected Issues

There has been an explosion of interest in ionic liquids in the last five years that has resulted in the discovery of a vast number of new ionic liquids with a wide range of interesting applications. Although ionic liquids are invariably described as highly stable green solvents, thorough investigations quantifying their purity, stability, biodegradability, and toxicity have lagged behind the pace of other research in the area. This review addresses these key issues and summarizes the approaches that have been developed for recycling ionic liquids.

Beta-phenylethylamines and the isoquinoline alkaloids

This review covers beta-phenylethylamines and isoquinoline alkaloids and compounds derived from them, including further products of oxidation, condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2001 to June 2002 is reviewed, with 581 references cited.

TEMPO-catalyzed aerobic oxidation of alcohols to aldehydes and ketones in ionic liquid [bmim][PF6]

[reaction: see text]. A simple and mild TEMPO-CuCl catalyzed aerobic oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones in ionic liquid [bmim][PF6] with no trace of overoxidation to carboxylic acids has been developed. The product can be isolated by a simple extraction with organic solvent, and the ionic liquid can be recycled or reused.