Synlett 2010(5): 692-706  
DOI: 10.1055/s-0029-1219527
ACCOUNT
© Georg Thieme Verlag Stuttgart ˙ New York

Gold-Catalyzed Reaction of Propargylic Carboxylates via an Initial 3,3-Rearrangement

Shaozhong Wang, Guozhu Zhang, Liming Zhang*
Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106
Fax: +1(805)8934120; e-Mail: zhang@chem.ucsb.edu;
Further Information

Publication History

Received 16 September 2009
Publication Date:
18 February 2010 (online)

Abstract:

Gold-catalyzed 3,3-rearrangement of propargylic carboxylates offers a versatile entry into a range of fascinating subsequent transformations, leading to various functional structures.

1 Introduction

1.1 Two Competing Mechanistic Pathways

1.2 Experimental Evidence for 3,3-Rearrangement

2 Synthetic Application via Gold-Containing Oxocarbenium Intermediates

2.1 General Considerations/Design

2.2 Using Indole-3-acetyl as the Acyl Group

2.3 Varying the R³ Group

2.3.1 Using Enyne Substrates (R³ = Alkenyl)

2.3.2 Using the TMSCH2 Group as R³

2.4 Using the Aryl Group for R¹ (R² = H)

2.5 Hydrolytic Treatment

2.5.1 Formation of Enones

2.5.2 Formation of α-Iodo/Bromoenones

2.6 Intramolecular Acyl Migration

2.7 Incorporating Gold(I)/Gold(III) Catalysis

2.7.1 Gold-Catalyzed Oxidative Homo-Coupling

2.7.2 Gold-Catalyzed Oxidative Cross-Coupling Reaction

2.7.3 Gold-Catalyzed Oxidative C-O Bond Formation

3 Attack of Au-Activated Carboxyallene at the β- or
γ-Position

3.1 Nucleophilic Attack at the γ-Position

3.2 Nucleophilic Attack at the β-Position

4 Carboxyallenes as Nucleophiles

5 Summary

1

Current address: Department of Chemistry, Nanjing University, Nanjing, P. R. of China

2

Previous address: Department of Chemistry, University of Nevada, Reno, NV 89557

20

ConQuest® searching of the Cambridge structural database for structures containing C(sp²)-Au(I)(PPh3) bonds gave an average bond length of ˜2.04 Å, while the bond length of C(sp²)-C(sp³) is 1.50 Å.