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Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis : Novel ...

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632 NITRONATES<br />

Table 3.23 The k<strong>in</strong>etic <strong>and</strong> activation parameters for (349 + 352) C,C-coupl<strong>in</strong>gs<br />

Nucleo- Ref. N <strong>and</strong> (s) k(20 ◦ C), ΔG # 20C, ΔH # , ΔS # ,<br />

Cat. 4 phile Product parameters (481) E mol −1 · s −1 kJ/mol kJ/mol J/mol·K<br />

(352a) (353a) 5.46 (0.89) −3.69 37.7 62.9 ± 3.7 42.9 ± 1.5 −68.1 ± 7.4<br />

(349f) (352e) (353a) 3.09 (0.90) −3.37 0.55 73.2 ± 4.0 49.5 ± 1.8 −80.7 ± 7.8<br />

(352f) (353c) 5.13 (0.90) a −4.21 6.55 67.1 ± 4.4 45.2 ± 1.9 −74.9 ± 8.6<br />

(352 g) (353 d) 6.22 (0.96) −6.08 1.37 70.9 ± 1.7 51.1 ± 0.7 −67.6 ± 3.3<br />

(349f ′ ) (352a) (353e) 5.46 (0.89) −3.70 36.6 63.0 ± 3.6 41.7 ± 1.5 −72.4 ± 7.2<br />

(352b) (353f) 4.41 (0.96) −4.54 0.74 72.4 ± 2.3 39.2 ± 1.0 −113.6 ± 4.4<br />

(352c) (353b) 5.41 (0.91) −5.45 0.92 71.9 ± 2.3 43.9 ± 1.0 −95.6 ± 4.3<br />

(352 d) (353 g) 6.22 (0.96) −5.99 1.65 70.5 ± 1.7 51.7 ± 0.7 −64.1 ± 3.1<br />

(349i) (352 h) (353 h) 10.32 (0.79) −10.21 1.23 71.2 ± 1.1 31.4 ± 0.5 −135.9 ± 2.3<br />

a s value for (352f) was estimated as the same as for (352a) <strong>and</strong> (352e) <strong>in</strong> Reference 481.<br />

Ph<br />

H<br />

O N<br />

+ OSi<br />

349f,f′<br />

for 349f, 353d: Si – Me2Bu t Si<br />

for 349f′, 353g: Si – Me3Si<br />

Ph<br />

OSi<br />

352d,g<br />

k1<br />

Ph<br />

O N OSi<br />

OSi<br />

A<br />

Ph<br />

C,C – Coupl<strong>in</strong>g k (−50 ° C, M −1 S −1 )<br />

OTf −<br />

k2<br />

fast<br />

349f + 352d 353d 1.38 × 10 −3 ± 2.9 × 10 −4<br />

349f + 352g 353d 1.40 × 10 −3 ± 4.0 × 10 −4<br />

349f′+ 352g 353g 1.41 × 10 −3 ± 0.4 × 10 −4<br />

+<br />

Scheme 3.207<br />

TfOSi<br />

Ph<br />

O N<br />

353d,g<br />

O<br />

OSi<br />

Ph<br />

for 352d: Si – Me2Bu t Si<br />

for 352g: Si – Me 3Si

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