Palladium-Catalyzed Reaction of Diselenide with Isocyanide
Palladium-Catalyzed Reaction of Diselenide with Isocyanide
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钯催化二硒化物与异氰化物的反应
DOI：
10.1021/om970936p
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发表时间：
1998
期刊：
影响因子：
2.8
通讯作者：
H. Kurosawa
中科院分区：
文献类型：
--
作者：
H. Kuniyasu;A. Maruyama;H. Kurosawa
描述了Pd催化的反应，该反应提供了异氰化物插入Pd−Se键的第一个例子。四(三苯基膦)钯[Pd(PPh3)4]催化二硒醚(HASH)2(1a)与异氰化物ArNC(2)(Ar=4-MeC6H4)反应生成加合物(HASH)(CNAr)m(SEAR)(m=2，3)。测定了钯中间体反式Pd(SeAr)2(CNAr)(PPh3)(7a)的X射线晶体结构。与使用二硫化物的钯催化反应形成鲜明对比的是，不产生1：1加合物3a(m=1)。7a与1a的化学计量反应也不提供3a。这些事实表明，只有当两个以上的异氰酸酯插入7a的Pd−Se键(S)得到Pd[(CNAr)p(SEAR)][(CNAr)q(SEAR)]Ln(p，q≥0)(10a)时，才能发生1：M加合物的还原消除。相反，二碲化物(PhTe)2(1c)与2的反应不被Pd络合物催化，部分原因是钯(II)碲酸盐中间体的不溶性和不稳定性。
A Pd-catalyzed reaction providing the first example of insertion of isocyanide into a Pd−Se bond is described. Tetrakis(triphenylphosphine)palladium [Pd(PPh3)4] catalyzes the reaction of a diselenide (ArSe)2 (1a) with an isocyanide ArNC (2) (Ar = 4-MeC6H4) to afford the adducts (ArSe)(CNAr)m(SeAr) (m = 2, 3). An X-ray crystallographic structure of the palladium intermediate trans-Pd(SeAr)2(CNAr)(PPh3) (7a) is determined. In marked contrast to the Pd-catalyzed reaction using a disulfide, the 1:1-adduct 3a (m = 1) is not produced. The stoichiometric reaction of 7a with 1a also did not provide 3a. These facts suggest that the reductive elimination of 1:m-adducts takes place only when more than two isocyanides are inserted into Pd−Se bond(s) of 7a to give Pd[(CNAr)p(SeAr)][(CNAr)q(SeAr)]Ln (p, q ≥ 0) (10a). In contrast, the reaction of ditelluride (PhTe)2 (1c) with 2 is not catalyzed by the Pd complex due in part to the insolubility and instability of the palladium(II) tellurolate intermediates.