Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
J Am Chem Soc. 2009 Dec 9;131(48):17532-3. doi: 10.1021/ja906880d.
Addition of 2 equiv of B(C(6)F(5))(3) to [Cp*(2)Co][U(V)O(2)((Ar)acnac)(2)] (1) [(Ar)acnac = ArNC(Ph)CHC(Ph)O; Ar = 3,5-(t)Bu(2)C(6)H(3)] results in the formation of [Cp*(2)Co][U(V){OB(C(6)F(5))(3)}(2)((Ar)acnac)(2)] (2) in good yield. Reduction of 2 with 1 equiv of Cp*(2)Co generates Cp*(2)Co[U(IV){OB(C(6)F(5))(3)}(2)((Ar)acnac)(2)] (3), also in good yield. This reaction is chemically reversible, as shown by the reaction of 3 with AgOTf, which regenerates 2. Interestingly, addition of only 1 equiv of B(C(6)F(5))(3) to 1 does not produce the monofunctionalized U(V) complex. Instead, the products of disproportionation, namely, 3 and U(VI)O(2)((Ar)acnac)(2), are observed in a 1:1 ratio.
向 [Cp*(2)Co][U(V)O(2)((Ar)acnac)(2)]（1）（[Cp*(2)Co] = 五羰基合铁(0)二茂铁；(Ar)acnac = ArNC(Ph)CHC(Ph)O；Ar = 3,5-(t)Bu(2)C(6)H(3)）中加入 2 当量的 B(C(6)F(5))(3)，可高产率得到 [Cp*(2)Co][U(V){OB(C(6)F(5))(3)}(2)((Ar)acnac)(2)]（2）。用 1 当量的 Cp*(2)Co 将 2 还原，可生成同样高产率的Cp*(2)Co[U(IV){OB(C(6)F(5))(3)}(2)((Ar)acnac)(2)]（3）。该反应是化学可逆的，如 3 与 AgOTf 的反应所示，可重新生成 2。有趣的是，向 1 中仅加入 1 当量的 B(C(6)F(5))(3)，不会生成单官能化的 U(V)络合物。相反，观察到歧化反应的产物，即 3 和 U(VI)O(2)((Ar)acnac)(2)，以 1:1 的比例存在。
