Synlett 2011(3): 294-307  
DOI: 10.1055/s-0030-1259332
ACCOUNT
© Georg Thieme Verlag Stuttgart ˙ New York

Direct Carbon-Hydrogen Bond Functionalization of Heterocyclic Compounds

Koji Hirano, Masahiro Miura*
Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
Fax: +81(6)68797362; e-Mail: miura@chem.eng.osaka-u.ac.jp;
Further Information

Publication History

Received 5 November 2010
Publication Date:
19 January 2011 (online)

Abstract

This account summarizes our recent results on the direct carbon-hydrogen bond functionalization of heterocyclic compounds, including arylation, alkenylation, alkynylation, alkylation, and amination. In the arylation and alkenylation reactions, we mainly focus on the potential of less-expensive first transition elements and demonstrate the good activities of copper and nickel catalysts which are similar to those of conventional palladium ones. The catalytic systems based on copper or nickel also enable direct alkynylation with simple terminal alkynes, as well as with alkynyl halides. On the other hand, a new application of palladium catalysts in the relatively difficult direct alkylation is shown. In addition to the development of catalysts, we introduce chloramines as new, efficient electrophilic amination reagents for heteroaromatic carbon-hydrogen bonds; these compounds allow the concise synthesis of amino-substituted azoles that are of great interest in pharmaceutical and medicinal chemistry.

1 Introduction

2 Direct Arylation and Alkenylation

2.1 Copper-Mediated Arylation with Aryl Iodides

2.2 Nickel-Catalyzed Arylation with Aryl Bromides

2.3 Nickel-Catalyzed Arylation and Alkenylation with Organo­silanes and Organoboron Compounds

3 Direct Alkynylation

3.1 Nickel- and Copper-Catalyzed Alkynylation with Alkynyl Bromides

3.2 Nickel- and Copper-Catalyzed Alkynylation with Terminal Alkynes

4 Direct Alkylation

4.1 Palladium-Catalyzed Benzylation with Benzyl Carbonates

4.2 Palladium- and Nickel-Catalyzed Alkylation with Unactivated Alkyl Bromides and Chlorides

5 Direct Amination

5.1 Copper-Catalyzed Direct Amination with Chloramines

6 Summary and Outlook