Catalytic Enantioselective Synthesis of Oxindoles and Benzofuranones Bearing a Quaternary Stereocenter and Reactions of Palladium Bisphosphine Complexes Relevant to Catalytic C-C Bond Formation
Author | : Ivory Derrick Hills |
Publisher | : |
Total Pages | : 376 |
Release | : 2004 |
ISBN-10 | : OCLC:59133112 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Catalytic Enantioselective Synthesis of Oxindoles and Benzofuranones Bearing a Quaternary Stereocenter and Reactions of Palladium Bisphosphine Complexes Relevant to Catalytic C-C Bond Formation written by Ivory Derrick Hills and published by . This book was released on 2004 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part I the development of a new method for the construction of oxindoles and benzofuranones bearing quaternary stereocenters is discussed. A planar-chiral PPY derivative catalyzes the O-to-C acyl group migration (Black rearrangement) in a highly efficient and enantioselective manner. The utility of this method is further demonstrated by the formal total synthesis of the natural product aplysin. In Part II reactivity of bisphosphine palladium-complexes is discussed. It is shown that the oxidative addition of bisphosphine palladium-complexes bearing P(t-Bu2)Me occurs through an SN2-type mechanism. This discovery allows us rationalize the difference in catalytic activity between Pd(P(t-Bu2)Me)2 and Pd(P(t-Bu2)Et)2 for the cross-coupling of alkyl electrophiles. The reductive elimination of H-X from bisphosphine palladium-hydride complexes is also discussed. The discovery that (P(t-Bu)3)2PdHCl undergoes facile reductive elimination in the presence of Cy2NMe, while (PCy3)2PdHCl does not, is explained using X-ray crystal structures. These reactivity patterns may help to explain why Pd(P(t-Bu)3)2 is a much better catalyst than Pd(PCy3)2 for the Heck coupling of aryl chlorides. Finally, Part III describes preliminary work on a palladium-hydride catalyzed isomerization of allylic alcohols as well as initial attempts to study the mechanism of nickel-catalyzed cross-couplings of secondary alkyl-electrophiles.