Studies on the Zinc-mediated Phenyl and Alkynyl addition to Carbon-heteroatom double bonds

This thesis describes the work carried out by the author in the field of enantioselective dialkylzinc-mediated carbon-carbon bond forming reactions. In particular, the asymmetric addition of C(sp2) and C(sp) nucleophiles to carbon-heteroatom double bonds was the subject of this research. In the first part of the thesis, the synthesis of new chiral compounds to be used as ligands for the enantioselective phenyl addition to aldehydes is described. Novel alfa-hydroxy oxazolines derived from such precursors as mandelic acid, benzoylformic acid and ethyl oxamate were synthesized and used as chiral promoters for the reaction of a mixture of triphenylborane and diethylzinc with aromatic and aliphatic aldehydes. As a result, chiral secondary alcohols were obtained in good yields with up to 81% enantiomeric excess. In the second part of this work, the synthesis of propargylic amines by the reaction of a mixture of a terminal acetylene and dimethylzinc with imines was developed. Whereas it was found that the reaction can proceed also in the absence of ligands, providing an easy and high yielding way to prepare racemic propargylamines, the addition to the reaction mixture of a tertiary amino alcohol, having a norephedrine-based structure, as a chiral promoter allowed to obtain the products in good to high yields with up to 97% ee.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2006

Author dc:creator

• Zani, Lorenzo

Contributors dc:contributor

• Bolm, Carsten

• info:eu-repo/classification/ddc/540
• Chemie
• Asymmetrische Synthese
• Metallorganische Chemie
• Diarylmethanole
• Propargylamine
• Dialkylzinkverbindungen
• Dialkylzinc compounds

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-122885%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61206