Synthesis of Aromatic Heterocycles and Carbocycles Through Tandem Palladium-Catalyzed Cross-Coupling Reactions of Gem-dihaloolefins
Author | : Christopher Scott Bryan |
Publisher | : |
Total Pages | : 798 |
Release | : 2010 |
ISBN-10 | : OCLC:747802968 |
ISBN-13 | : |
Rating | : 4/5 (68 Downloads) |
Book excerpt: Our group has developed a strategy for the synthesis of benzofused carbocycles and heterocycles through tandem palladium-catalyzed reactions of gem-dibromoolefins. In these syntheses, one bromide undergoes a Pd-catalyzed cyclization reaction, and the other participates in an orthogonal inter- or intramolecular Pd-catalyzed reaction to functionalize or annulate that ring, respectively.Chapter 2 describes the synthesis of benzothiophenes through the combination of a Pd-catalyzed C--S coupling with an orthogonal Suzuki, Heck, or Sonogashira reaction. This represents the first example of the incorporation of Pd-catalyzed C--S coupling into a tandem reaction.Chapter 1 describes the pairing of an intramolecular C--N bond forming reaction (the Buchwald- Hartwig coupling) with an intramolecular direct arylation for the synthesis of fused indole derivatives. A range of previously unknown heterocycles were synthesized through this method.In Chapter 3, a tandem intramolecular Heck / intermolecular Suzuki reaction is described for the synthesis of methyleneindenes. Studies on this reaction have provided advanced understanding of the mechanism, including how variation of the ligand controls the regioselectivity of the reaction.