Synlett 2011(9): 1189-1194  
DOI: 10.1055/s-0030-1259946
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© Georg Thieme Verlag Stuttgart ˙ New York

Space Integration of Reactions: An Approach to Increase the Capability of Organic Synthesis

Jun-ichi Yoshida*, Kodai Saito, Toshiki Nokami, Aiichiro Nagaki
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
Fax: +81(75)3832727; e-Mail: yoshida@sbchem.kyoto-u.ac.jp;
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Publikationsverlauf

Received 23 November 2010
Publikationsdatum:
07. April 2011 (online)

Abstract

This article provides a brief outline of the concept of ­reaction integration in flow systems and some examples. The use of flow microreactors enables space integration of multiple reactions, especially those involving highly reactive short-lived reactive intermediates to enhance the power and speed of organic synthesis.

2

A project of ‘Organic Synthesis based on Reaction Integration. Development of New Methods and Creation of New Substances’ supported by Grant-in-Aid for Scientific Research on Innovative Areas, The Ministry of Education, Culture, Sports, Science, and Technology, Japan, started in 2009.

7

Multicomponent(coupling) reactions are reactions that convert more than two components directly into their products in a single reactor. Therefore, they can be also carried out in one-pot sequential way.

13

Integrated chemical synthesizer was proposed by Bard in 1994. See: Bard, A. J. Integrated Chemical Systems; Wiley: New York, 1994.

14

The name of domino reaction was derived from the game where one puts up several domino pieces in one row and in agreement with the time-resolved succession of reactions,
if one knocks over the first domino, all the others follow without changing the conditions. However, we should keep in mind that all the molecules in a reaction vessel do not start the domino at once. It is difficult to activate all reactant molecules coherently. The molecules are activated indivi-dually and participate in the reaction (and also domino sequence) at different times. Therefore, all the reactions in the sequence take place simultaneously from a macroscopic point of view. Therefore, reaction times (time required for converting most of the reactant molecules) often range from minutes to hours, although the time required for the reaction for a single molecule is several hundred femtoseconds to picoseconds.

15

Life times of radical intermediates are usually much shorter than millisecond. Therefore, space integration of radical reactions is practically impossible at present, although there are many examples of time and space integration of radical reactions.