Nitrogen-to-metal multiple bond functionalities: The reaction of calix[4]arene-W(IV) with azides and diazoalkanes
Nitrogen-to-metal multiple bond functionalities: The reaction of calix[4]arene-W(IV) with azides and diazoalkanes
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DOI：
10.1021/om000612s
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发表时间：
2001-02-19
期刊：
影响因子：
2.8
通讯作者：
Rizzoli, C
中科院分区：
文献类型：
--
作者：
Guillemot, G;Solari, E;Rizzoli, C
[{杯[4]-（O）（4）}W（eta（2）-C6 H 10）]，2被用作中心键合到氧代表面上的W-IV-d（2）的来源，这已被杯[4]芳烃四阴离子在与重氮烷烃和有机叠氮化物的反应中模拟。与Ph 2CN 2的反应导致形成金属腙[{杯[4]-（O）（4）}W= N-NCPh 2]，5，其在空腔内结合（BuNC）-N-t，6，或者其可以被还原成双核W-V衍生物[W-W，2.646（1）埃]，其中两种金属通过络合物7中的二苯基肼基配体桥接，[{杯[4]-（O）（4）}（2）W-2（mu-N-N = CPh 2）（2）Na-2]。2与有机叠氮化物（RN 3）的反应强烈依赖于叠氮化物官能团处的R取代基的性质。与RN 3 [R = SiMe 3; CPh 3]的反应发生在外位的金属处，导致烷基亚氨基衍生物[{杯[4]-（O）（4）}W=N-R] [R = SiMe 3; 8; R = CPh 3，9]，其结合在空腔ButNC内，分别导致10和11。相反，2与PhN 3的反应发生在杯芳烃空腔内，得到三氮烯基衍生物[{mu -杯[4]-（O）（4）}（2）（W=N-N=NPh）（2）]，12。用有机叠氮化物的结果表明，在exo和endo位置的金属处遵循两种不同的途径。在前一种情况下，由于空间原因，叠氮化物与类卡宾金属的1，3偶极加成先于烷基酰亚胺的形成。在PhN 3的情况下，杯腔的大小阻止了相同的途径。在HN 3的情况下，反应应该进行，其中HN 3将金属与空腔内的质子化氮结合并分解为亚氨基官能团[{μ-杯[4]-（O）（4）}（2）（W=NH）（2）]，13。已经报道了W-VI的芳基亚氨基衍生物的替代合成路线。[杯[4]-（ONa）（4）（THF）（2）]与[对甲苯基-N= WCl 4]的反应产生[μ-杯[4]-W=N-p-甲苯基]，14，其在溶液中与相应的二聚形式[{μ-杯[4]}（2）-W=N-p-甲苯基]，15平衡。
The [{calix[4]-(O)(4)}W(eta (2)-C6H10)], 2, has been used as a source of W-IV-d(2) center-bonded to an oxo surface, which has been modeled by the calix[4] arene tetraanion in the reaction with diazoalkanes and organic azides, The olefin is easily displaced by both substrates. The reaction with Ph2CN2 led to the formation of metallahydrazone, [{calix[4]-(O)(4)}W=N-NCPh2], 5, which binds (BuNC)-N-t inside the cavity, 6, or it can be reduced to a,dinuclear W-V derivative [W-W, 2.646(1) Angstrom], where the two metals are bridged by a diphenylhydrazido ligand in complex 7, [{calix[4]-(O)(4)}(2)W-2(mu -N-N=CPh2)(2)Na-2]. The reaction of 2 with organic azides (RN3) is strongly dependent on the nature of the R substituent at the azide functionality. The reaction with RN3 [R = SiMe3; CPh3] occurs at the metal in the exo position, leading to alkylimido derivatives [{calix[4]-(O)(4)}W=N-R] [R = SiMe3; 8; R = CPh3, 9], which bind inside the cavity ButNC, leading to 10 and 11 respectively. The reaction of 2 with PhN3, on the contrary, occurs inside the calixarene cavity, leading to the triazenido derivative [{mu -calix[4]-(O)(4)}(2)(W=N-N=NPh)(2)], 12. The results of a,with organic azides show that two different pathways are followed at the metal in the exo and endo positions. In the former case, for steric reasons, the 1,3 dipolar addition of the; azide to; the carbenoid metal precedes the formation of the alkylimido. In the case of PhN3, the size of the calix cavity prevents the same pathway. In the case of HN3 the reaction is supposed to proceed with HN3 binding the metal with the protonated nitrogen inside the cavity and decomposing to the imido functionality [{mu -calix[4]-(O)(4)}(2)(W=NH)(2)], 13. An alternative synthetic route to arylimido derivatives of W-VI has been reported, The reaction of [calix[4]-(ONa)(4)(THF)(2)] with [p-tolyl-N=WCl4] led to [mu -calix[4]-W=N-p-tolyl], 14, which is in equilibrium in solution with the corresponding dimeric form [{mu -calix[4]}(2)-W=N-p-tolyl], 15.