Selective carbon -carbon bond formation reactions catalyzed by various transition metals and their applications to the syntheses of natural products

Ze Tan, Purdue University

Abstract

In this thesis work, an extensive study was carried out on the Pd-catalyzed cross-coupling between organozinc compounds and cyclic α-iodoenones and α-iodo-α,β-unsaturated esters. Through optimization of reaction conditions, a successful protocol was developed for the Pd-catalyzed α-alkynylation of cyclic α-iodoenones using alkynylzincs. This optimized procedure has been applied to the synthesis of (±)-harveynone and (±)-tricholomenyn A. A formal synthesis of natural product epolactaene was accomplished in a completely stereoselective manner. Key features of the synthesis include the successful development of Pd-catalyzed α-alkenylation of α-iodo-α,β-unsaturated esters and novel synthesis trimethylsilylated epoxylactone. Other important transformations involve the use of Zr-catalyzed carboalumination protocol, Pd-catalyzed homopropargylation, Pd-catalyzed ethynylation and Ti-catalyzed hydromagnesiation. A third part of this thesis will focus on the use of palladium-catalyzed carbonylative carbopalladation cascade cyclizations reaction for the synthesis of natural product nagilactone F. In summary, the tricyclic core of nagilactone F was successfully constructed and the cyclizations step was successfully tested. It was the first time that such method has been used in the synthesis of complex natural product, although several more steps are required for its final completion. The final chapter will discuss some most recent results on the zirconium-catalyzed enantioselective carboalumination and its application to the synthesis of natural product dianeackerones.

Degree

Ph.D.

Advisors

Negishi, Purdue University.

Subject Area

Organic chemistry

COinS