Synthesis 2014; 46(12): 1555-1572
DOI: 10.1055/s-0033-1338631
review
© Georg Thieme Verlag Stuttgart · New York

Dehydrogenative Heck Annelations of Internal Alkynes

Jean Le Bras
Institut de Chimie Moléculaire de Reims, UMR 7312 CNRS - Université de Reims Champagne-Ardenne, B.P. 1039, 51687 Reims Cedex 2, France   Fax: +33(3)26913166   Email: jacques.muzart@univ-reims.fr
,
Jacques Muzart*
Institut de Chimie Moléculaire de Reims, UMR 7312 CNRS - Université de Reims Champagne-Ardenne, B.P. 1039, 51687 Reims Cedex 2, France   Fax: +33(3)26913166   Email: jacques.muzart@univ-reims.fr
› Author Affiliations
Further Information

Publication History

Received: 14 January 2014

Accepted after revision: 05 February 2014

Publication Date:
05 May 2014 (online)


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Abstract

This review covers the palladium-catalyzed annelations of internal alkynes through reactions leading to the loss of only two hydrogens from the substrates. They occur via (i) dual C–H bond activation, (ii) both C–H and N–H bond activation, (iii) successive amino(or oxy)palladation and C–H bond activation, or (iv) C–H bond activation followed by a Heck-type process. The proposed mechanisms are described with, in some cases, personal commentary.

1 Introduction

2 Synthesis of Aryl Rings

2.1 Via Aryl–Alkyne Coupling

2.2 Via Allylaryl–Alkyne Coupling

2.3 Via Cyclopentadienyl–Alkyne Coupling

2.4 Via Benzoylacetate–Alkyne Coupling

2.5 Via Indole–Alkyne Coupling

2.6 Via Benzothiophene–Alkyne or Benzofuran–Alkyne Coupling

3 Synthesis of Pyrrole Rings

3.1 Via Imidazo[1,2-a]pyridine–Alkyne Coupling

3.2 Via Aniline–Alkyne Coupling

3.3 Via Enamine–Alkyne Coupling

3.4 Via Enamide–Alkyne Coupling

3.5 Via Indole–Alkyne Coupling and Rearrangement

4 Synthesis of Pyridinone Rings

4.1 Via Indole-carboxamide–Alkyne Coupling

4.2 Via Arylcarboxamide–Alkyne Coupling

5 Synthesis of Furan Rings

6 Synthesis of Azepine Rings

7 Synthesis of Spiroindenes

8 Synthesis of Cyclopentadiene Rings

8.1 Via Arylalkyne Self-Coupling

8.2 Via Alkenylindole–Alkyne Coupling

9 Conclusion