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. Author manuscript; available in PMC: 2009 Oct 1.
Published in final edited form as: J Am Chem Soc. 2008 Sep 6;130(39):12907–12911. doi: 10.1021/ja8050487

Table 3.

Synthesis of trans-Disubstituted and -Trisubstituted PyrazolidinesaInline graphic

Entry Substrate RS RL R1 Product Yield(%)b drc
1 7 H C3H7 p-ClPh 35 70 >20:1 (7:1)
2d 7 H C3H7 β-styryl 36 54 5:1 (5:1)
3 30 H Ph m-MePh 37 66 13:1 (10:1)
4 30 H Ph p-tBuO2CPh 38 55 >20:1 (>20:1)
5d 30 H Ph α-styryl 39 63 11:1 (8:1)
6d 31 Me Me p-tBuO2CPh 40 80 -
7d 32 (CH2)5 N-(Bn)-5-indolyl 41 56 -
8 33 Me Ph p-PhPh 42 83 6:1 (6:1)
9 34 Me tBu 6-MeO-2-naphthyl 43 73 >20:1 (12:1)
a

Conditions: 1.0 equiv hydrazine, 1.2 equiv ArBr, 1.2 equiv NaOtBu, 2 mol % Pd(OAc)2, 2 mol % Dpe-phos, toluene (0.25 M), 70 °C, 4-12 h.

b

Isolated yield, average of two or more experiments.

c

Diastereomeric ratios are reported for the isolated products. Diastereomeric ratios in parentheses were observed in crude reaction mixtures.

d

The reaction was conducted using 1.2 equiv ArBr and 1.2 equiv of NaOtBu at 70 °C.