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. Author manuscript; available in PMC: 2017 Sep 21.
Published in final edited form as: J Am Chem Soc. 2016 Sep 9;138(37):12297–12302. doi: 10.1021/jacs.6b08727

Table 2.

Optimizations of catalyst and reaction conditions for enantioselective isomerization of 1aa

graphic file with name nihms822675u3.jpg
Entry cat. mol% of cat. Base presentedin the reaction Solvent t (h) conv. (%)b ee (%)b
1 QD-9a 0.5 No Toluene/CHCl3 = 7/3 4 76 92
2 QD-9b 0.5 No Toluene/CHCl3 = 7/3 4 97 93
3 QD-9c 0.5 No Toluene/CHCl3 = 7/3 4 98 95
4 QD-9c 0.2 No Toluene/CHCl3 = 7/3 24 77 95
5 OD-9c 0.2 solid K2CO3 Toluene/CHCl3 = 7/3 12 100 95
6 QD-9c 0.02 solid K2CO3 Toluene 24 100 96c
7 QD-9c 0.01 solid K2CO3 Toluene 24 97 96
8 Q-9c 0.05 solid K2CO3 Toluene 24 100 −93
a

Betaine catalysts QD-9 and Q-9c were preformed from treatment of the corresponding precursors PQD-9 and PQ-9c with base (see supporting information for details). Reactions were run with 1a (0.025 mmol) in solvent (0.25 mL) indicated. The ratio of 2a/4a was determined to be greater than 99/1 by HPLC analysis.

b

Determined by HPLC analysis.

c

Absolute configuration was determined to be R. See Supporting Information for details.