from asymmetric conjugate addition of alkylzirconium reagents to linear trisubstituted enones †

Content Provider	Semantic Scholar
Author	Gao, Zhenbo
Copyright Year	2016
Abstract	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-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.
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Alternate Webpage(s)	https://pubs.rsc.org/en/content/articlepdf/2017/SC/C6SC02811J
Alternate Webpage(s)	http://www.rsc.org/suppdata/c6/sc/c6sc02811j/c6sc02811j1.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article