(3,5-dichloro-2,4,6-trifluorophenyl)bis(triphenyl-5-arsanyl)palladium(IV) bromide | 213135-40-1

• 英文名称: (3,5-dichloro-2,4,6-trifluorophenyl)bis(triphenyl-5-arsanyl)palladium(IV) bromide
• CAS: 213135-40-1
• 化学式: C₄₂H₃₀As₂BrCl₂F₃Pd
• 分子量: 998.769
• InChiKey: LIKULJOKFMSMCW-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
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• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为反应物：
  描述：

  (3,5-dichloro-2,4,6-trifluorophenyl)bis(triphenyl-5-arsanyl)palladium(IV) bromide 、 三丁基乙烯基锡 以 四氢呋喃 为溶剂， 生成 (Ph3As)2Pd 、 三正丁基溴化锡
  参考文献：
  名称：

  Mechanism of the Stille Reaction. 1. The Transmetalation Step. Coupling of R¹I and R²SnBu₃ Catalyzed by trans-[PdR¹IL₂] (R¹ = C₆Cl₂F₃; R² = Vinyl, 4-Methoxyphenyl; L = AsPh₃)

  摘要：

  The so far accepted mechanism of the Stille reaction (palladium-catalyzed cross-coupling of organotin reagents with organic electrophiles) is criticized. Based on kinetic studies on catalytic reactions, and on reactions with isolated intermediates, a corrected mechanism is proposed. The couplings between (RI)-I-1 (1) (R-1 = C-6- Cl2F3 3,5-dichlorotrifluorophenyl) and (RSnBu3)-Sn-2 (R-2 = CH=CH2, 2a; C6H4-4-OCH3, 2b), catalyzed by trans-[(PdRI)-I-1(AsPh3)(2)] (3a), give R-1-R-2 and obey a first-order law, r(obs) = a[3a][2a]/(b + [AsPh3]), with a (2.31 +/- 0.09) x 10(-5) s(-1) and b = (6.9 +/- 0.3) x 10(-4) mol L-1, for [1] [2a] = 0-0.2 mol L-1, [3a] = 0-0.02 mol L-1, and [AsPh3] = 0-0.07 mol L-1, at 322.6 K in THF, The only organopalladium(II) intermediate detected under catalytic conditions is 3a. The apparent activation parameters found for the coupling of 1 with 2a support an associative transmetalation step (Delta H-obs(double dagger) = 50 +/- 2 kJ mol(-1), Delta S-obs(double dagger) = -155 +/- 7 J K-1 mol(-1) in THF; and Delta H-obs(double dagger) = 70.0 +/- 1.7 kJ mol(-1), Delta S-obs(double dagger) = -104 +/- 6 J K-l mol(-1) in chlorobenzene, with [1](0) = [2](0) = 0.2 mol L-1, [3a] = 0.01 mol L-1). The reactions of 2a with isolated trans-[PdR1 X(AsPh3)(2)] (X = halide) show rates Cl > Br > I. From these observations, the following mechanism is proposed: Oxidative addition of (RX)-X-1 to PdLn, gives cis-[(PdRXL2)-X-1], which isomerizes rapidly to trans-[(PdRXL2)-X-1]. This trans complex reacts with the organotin compound following a S-E(2)(cyclic) mechanism, with release of AsPh3 (which explains the retarding effect of the addition of L), to give a bridged intermediate [(PdRL)-L-1(mu-X)(mu-R-2)SnBu3]. In other words, an L-for-R-2 substitution on the palladium leads R-2 and R-1 to mutually cis positions. From there the elimination of XSnBu3 yields a three-coordinate species cis-[(PdRRL)-R-1-L-2], which readily gives the coupling product R-1-R-2.

  DOI：

  10.1021/ja9742388
• 作为产物：
  描述：

  trans-[Pd(3,5-C6Cl2F3)Cl(AsPh3)2] 、 sodium bromide 以 二氯甲烷 、 丙酮 为溶剂， 以89%的产率得到(3,5-dichloro-2,4,6-trifluorophenyl)bis(triphenyl-5-arsanyl)palladium(IV) bromide
  参考文献：
  名称：

  Mechanism of the Stille Reaction. 1. The Transmetalation Step. Coupling of R¹I and R²SnBu₃ Catalyzed by trans-[PdR¹IL₂] (R¹ = C₆Cl₂F₃; R² = Vinyl, 4-Methoxyphenyl; L = AsPh₃)

  摘要：

  The so far accepted mechanism of the Stille reaction (palladium-catalyzed cross-coupling of organotin reagents with organic electrophiles) is criticized. Based on kinetic studies on catalytic reactions, and on reactions with isolated intermediates, a corrected mechanism is proposed. The couplings between (RI)-I-1 (1) (R-1 = C-6- Cl2F3 3,5-dichlorotrifluorophenyl) and (RSnBu3)-Sn-2 (R-2 = CH=CH2, 2a; C6H4-4-OCH3, 2b), catalyzed by trans-[(PdRI)-I-1(AsPh3)(2)] (3a), give R-1-R-2 and obey a first-order law, r(obs) = a[3a][2a]/(b + [AsPh3]), with a (2.31 +/- 0.09) x 10(-5) s(-1) and b = (6.9 +/- 0.3) x 10(-4) mol L-1, for [1] [2a] = 0-0.2 mol L-1, [3a] = 0-0.02 mol L-1, and [AsPh3] = 0-0.07 mol L-1, at 322.6 K in THF, The only organopalladium(II) intermediate detected under catalytic conditions is 3a. The apparent activation parameters found for the coupling of 1 with 2a support an associative transmetalation step (Delta H-obs(double dagger) = 50 +/- 2 kJ mol(-1), Delta S-obs(double dagger) = -155 +/- 7 J K-1 mol(-1) in THF; and Delta H-obs(double dagger) = 70.0 +/- 1.7 kJ mol(-1), Delta S-obs(double dagger) = -104 +/- 6 J K-l mol(-1) in chlorobenzene, with [1](0) = [2](0) = 0.2 mol L-1, [3a] = 0.01 mol L-1). The reactions of 2a with isolated trans-[PdR1 X(AsPh3)(2)] (X = halide) show rates Cl > Br > I. From these observations, the following mechanism is proposed: Oxidative addition of (RX)-X-1 to PdLn, gives cis-[(PdRXL2)-X-1], which isomerizes rapidly to trans-[(PdRXL2)-X-1]. This trans complex reacts with the organotin compound following a S-E(2)(cyclic) mechanism, with release of AsPh3 (which explains the retarding effect of the addition of L), to give a bridged intermediate [(PdRL)-L-1(mu-X)(mu-R-2)SnBu3]. In other words, an L-for-R-2 substitution on the palladium leads R-2 and R-1 to mutually cis positions. From there the elimination of XSnBu3 yields a three-coordinate species cis-[(PdRRL)-R-1-L-2], which readily gives the coupling product R-1-R-2.

  DOI：

  10.1021/ja9742388