Acyclic quaternary centers from asymmetric conjugate addition of alkylzirconium reagents to linear trisubstituted enones

Journal article

Synthetic methods for the selective formation of all carbon quaternary centres in non-cyclic systems are rare. Here we report highly enantioselective Cu-catalytic asymmetric conjugate addition of alkylzirconium species to twelve different acyclic trisubstituted enones. A variety of sp(3)-hybridized nucleophiles generated by in situ hydrozirconation of alkenes with the Schwartz reagent can be introduced, giving linear products bearing quaternary centres with up to 98% ee. The method is tolerant of several important functional groups and 27 total examples are reported. The method uses a new chiral nonracemic phosphoramidite ligand in a complex with copper triflate as the catalyst. This work allows the straightforward stereocontrolled formation of a valuable structural motif using only a catalytic amount of chiral reagent.

Authors: Gao, Z; Fletcher, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Chemical Science
• Volume: 8
• Issue: 1
• Pages: 641-646
• Publication date: 2016-09-02
• Acceptance date: 2016-09-01
• DOI: 10.1039/c6sc02811j
• EISSN: 2041-6539
• ISSN: 2041-6520
• Language: English
• Keywords: Journal Article