Synlett 2007(7): 0999-1015  
DOI: 10.1055/s-2007-977434
ACCOUNT
© Georg Thieme Verlag Stuttgart · New York

Cation-Exchanged Montmorillonites as Solid Acid Catalysts for Organic Synthesis

Kiyotomi Kaneda*
Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
Fax: +81(6)68506260; e-Mail: kaneda@cheng.es.osaka-u.ac.jp;
Further Information

Publication History

Received 2 June 2006
Publication Date:
13 April 2007 (online)

Abstract

In this account the authors review a novel approach to design high-performance heterogeneous acid catalysts using montmorillonites as macroligands of active metal species for various C-C bond formations and one-pot syntheses. The catalytic systems using the above heterogeneous catalysts offer significant benefits in achieving environmentally friendly organic syntheses aiming towards green and sustainable chemistry. Furthermore, the present preparation method for the immobilization of metal species within the interlayer space is strikingly simple and allows a strong protocol for creating various nanostructured and functionalized metal-cation catalysts.

  • 1 Introduction

  • 2 Preparation and Characterization of Montmorillonite-­Enwrapped Cation Species

  • 2.1 Ti4+-mont and H+-mont as Brønsted Acids

  • 2.2 Cu2+-mont and Sc3+-mont as Lewis Acids

  • 3 Brønsted Acid Catalyzed Reactions

  • 3.1 Aromatic Alkylation Using Ti4+-mont Catalyst

  • 3.2 Miscellaneous Functional Group Transformations Using Ti4+-mont Catalyst

  • 3.3 Addition of 1,3-Dicarbonyls to Olefins Catalyzed by
    H+-mont Catalyst

  • 4 Lewis Acid Catalyzed C-C Bond-Forming Reactions

  • 4.1 Michael Reaction Using Cu2+-mont Catalyst

  • 4.2 Sakurai-Hosomi and Diels-Alder Reactions Catalyzed by Cu2+-mont

  • 4.3 Michael Reactions in Water Using Sc3+-mont Catalyst

  • 5 One-Pot Synthesis Using Solid Acid and Base Catalysts

  • 6 Conclusions