Skip to main content
. Author manuscript; available in PMC: 2011 Dec 17.
Published in final edited form as: Org Lett. 2010 Nov 19;12(24):5744–5747. doi: 10.1021/ol1025712

Table 2.

Chiral base-catalyzed enantioselective nitroalkane alkylations.

graphic file with name nihms254090u3.jpg
entry R1 R2 R3 ee (%)b yield(%)c (conv)
1 Me Ph Ph a 81/81 78(85)
2 Me pBrC6H4 Ph b 82/75 74(76)
3 Me pMeOC6H4 Ph c 81/81 68(88)
4 Me pF3CC6H4 Ph d 84/74 71(78)
5e Me oMePh Ph e 76/70 76(95)
6 Me 2Furyl Ph f 53/44 69(99)
7 Me nBu Ph g 76/74 51(56)
8d Me CO2Me Ph h 66/47 47(52)
9d,e Me CO2tBu Ph i 65/66 55(70)
10 H Ph Ph j 40/0 65(68)
11e Ph Ph Ph k 74/72 49(52)
12e 2,5-Me-Pyrrole Ph Ph l 72/69 69(79)
13 Me Ph pMeOC6H4 m 89/85 52(77)
14 Me Ph pO2NC6H4 n 37/43 63(86)
15e,f Me Ph Me o 66/67 65(87)
a

All reactions were performed on a 0.1 mmol scale using a standard 22 h reaction time and 7 equivalents of K2CO3. Diastereomeric ratios observed for crude reaction mixtures were measured by 1H NMR spectroscopy and ranged from 1:1 to 1.5:1 dr. See Supporting Information for complete details.

b

Enantiomeric ratios were measured using chiral stationary phase HPLC.

c

Isolated yields with conversions in parentheses.

d

3:1 dr observed.

e

72 h reaction time.

f

1.5 equivalents of nitroethane used.