Skip to main content
. Author manuscript; available in PMC: 2010 Aug 19.
Published in final edited form as: J Am Chem Soc. 2009 Aug 19;131(32):11625–11633. doi: 10.1021/ja904654j

Table 3.

NHC–Zn-catalyzed Enantioselective Allylic Alkylation Reactions of Trisubstituted Olefins with Dialkylzinc Reagentsa

graphic file with name nihms135256f10.jpg
entry substrate (R) (alkyl)2Zn product mol (%) 6a temp (°C) time (h) conv (%);b yield (%)c SN2′:SN2b erd
1 17a (Ph) Et2Zn 18 10 −30 48 95; 91 >98:<2 95.5:4.5
2 17a (Ph) n-Bu2Zn 19 10 −30 72 72; 71 >98:<2 95.5:4.5
3 17a (Ph) i-Pr2Zn 20 5 0 24 64; 52 >98:<2 95.5:4.5
4 17b (p-CF3C6H4) Et2Zn 21 5 −30 48 >98; 68 >98:<2 94.5:5.5
5 17c (p-NO2C6H4) Et2Zn 22 10 −30 48 >98; 82 >98:<2 94.5:5.5
6 17d (Cy) Et2Zn 23 5 −15 48 72; 58 >98:<2 97.5:2.5
7 17e (CO2t-Bu) n-Bu2Zn 24 5 −15 48 >98; 85 >98:<2 94:6
a

Reactions were performed under N2 atmosphere.

b

Conversion and site selectivity were determined by analysis of 400 MHz 1H NMR spectra of product mixtures prior to purification.

c

Yields of purified products.

d

Enantiomer ratios were determined by GLC analysis; see the Supporting Information for details.