Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

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Chapter Six
(CHtransCH2Si), 129.4 (ArCH-4), 129.5 (ArCH-3), 129.7 (ArCH-2), 133.8 (OCH2CHcis),
134.1 (OCH2CHtrans), 140.6 (ArC-1).
6.2.12 Preparation of 2-(4-trimethylsilanyl-but-2-enyl)isindole-1,3-dione (70) [8]
The title compound was prepared following the
method outlined by Gouverneur et al. [8] without
modification. A 100 cm 3 , three-necked round-bottom
flask was equipped with a magnetic stirring bar and
condenser and attached to a Schlenk line. After flame-drying under high vacuum, the flask
was cooled and filled with argon. The flask was charged with 2-allyl-isoindole-1,3-dione
(0.56 g, 3.0 mmol), allyltrimethylsilane (1.44 cm 3 , 9.0 mmol) and anhydrous DCM (10
cm 3 ). The reaction mixture was heated to reflux. Second generation Grubbs catalyst (15 %
mol, 126 mg, 0.15 mmol) was weighed into a V-shaped dropping tube in a dry box and then
transferred to the reaction flask, addition was in three portions over 48 h. The reaction was
left to reflux for 48 h. Purification by flash column chromatography [diethyl ether: hexane
(15:85)] and concentration in vacuo afforded the product as a white solid (0.64 g, 78 %),
(E/Z 3:1 ratio). δH 0.00 and 0.08 (9H, 2 x s, Me3Si), 1.47 (1.5H, d, 3 JHH = 8.2, 4 JHH = 1.2 Hz,
SiCH2-trans), 1.76 (0.5H, d, 3 JHH = 8.8 Hz, 4 JHH =1.5 Hz, SiCH2-cis), 4.25 (1.5H, d, 3 JHH = 6.7
Hz, 4 JHH =1.2 Hz, NCH2-trans), 4.30 (0.5H, d, 3 JHH = 7.0 Hz, 4 JHH = 1.5 Hz, NCH2-cis) 5.33-
5.45 (1H, m, Ha), 5.67 (0.25H, m, Hbcis), 5.81 (0.75H, dtt, 3 JHH = 15.2 Hz, 3 JHH = 8.2 Hz,
4 JHH = 1.2 Hz, Hbtrans), 7.73 (2H, dd, 3 JHH = 5.3 Hz, 4 JHH = 2.9 Hz, ArH-4) 7.87 (2H, dd,
3 JHH = 5.6 Hz, 4 JHH= 2.9 Hz, ArH-5); δC 0.00 (CH3-trans), 0.21 (CH3cis), 21.0 (SiCH2-cis), 24.8
(SiCH2-trans), 36.7 (NCH2-cis), 41.9 (NCH2-trans), 122.6 (CHcisCH2Si), 123.4 (CHtransCH2Si),
125.2 (ArCH-4), 132.8 (NCH2CHcis), 134.3 (ArC-3), 134.4 (NCH2CHtrans), 135.8 (ArCH-5),
170 (C=O).
6.2.13 Preparation of Benzoic acid 4-trimethylsilanyl-but-2-enyl ester (71) [8]
The title compound was prepared following the
method outlined by Gouverneur et al. [8] without
modification. A 100 cm 3 , three-necked round-
bottom flask was equipped with a magnetic stirring
bar and condenser and attached to a Schlenk line. After flame-drying under high vacuum,
the flask was cooled and filled with argon. The flask was charged with allyl benzoate (324
mg, 2 mmol), allyltrimethylsilane (0.96 cm 3 , 6 mmol) and anhydrous DCM (6 cm 3 ). The