Molybdenum metalloazines. New reagents for C=C bond formation by an organometallic analogue of the Wittig reaction
Molybdenum metalloazines. New reagents for C=C bond formation by an organometallic analogue of the Wittig reaction
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钼金属嗪。
DOI：
10.1021/ja00266a047
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
J. Schwartz
中科院分区：
文献类型：
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作者：
J. Smegal;I. K. Meier;J. Schwartz
长期以来，我们一直致力于开发新的，实用的有机金属方法学的广义烯烃合成。我们已经注意到1，Cp 2 Zr（PR 3）2与简单的正膦反应（虽然缓慢且产率低），得到Cp 2 Zr-亚烷基;各种各样的这些（最好通过替代路线制备）与含羰基的材料缩合，以高产率得到烯烃。[2]我们还发现，简单的正膦和Cp 2 Mo（PR 3）类似物容易反应，但所得产物与额外当量的叶立德迅速缩合，仅得到对称烯烃。3我们现在已经研究了低价钼化合物与重氮烷之间的反应，重氮烷是另一类容易获得的有机“叶立德”，它已经通过与各种金属络合物的相互作用作为反应性卡宾络合物的前体而得到广泛的应用。[4]与我们使用膦[3]或其他有关重氮化合物活化的结果[4]相反，我们发现重氮烷与简单的钼络合物反应迅速，产率高，得到加合物“金属嗪”;这些证明了对配位重氮单元碳端亲核攻击的敏感性。常规的正膦与这些加合物（其通常是羰基衍生物）反应，以“Wittig”反应的有机变化得到烯烃。与此相反，该经典方法另外产生氧化膦，
We have long been interested in developing new, practicable organometallic methodology for generalized olefin synthesis. We have noted1 that Cp2Zr (PR3) 2 reacts with simple phosphoranes (although slowly and in lowyield) to give Cp2Zr-alkylidenes; a variety of these (best made by an alternate route) condense with carbonyl-group-containing materials to give olefins in high yield. 2 We have also found that simple phosphoranes and Cp2Mo (PR3) analogues react readily, but the resulting product condenses rapidly with an additional equivalent of ylide to give only the symmetrical olefin. 3 We have now examined reactions between low-valent molybdenum compounds and diazoalkanes, another class of readily available organic “ylides” which has already enjoyed wide utili-zation as precursors of reactive carbene complexes through interaction with a variety of metallic complexes. 4 In contrast to our results using phosphoranes3 or of others with regard to diazo compound activation, 4 we find that diazoalkanesreact rapidly and in high yield with simple molybdenum complexesto give adducts,“metalloazines”; these demonstratesusceptibility to nucleophilic attack on the carbon end of the coordinated diazo unit. Conventional phosphoranes react with these adducts (which, ulti-mately, are carbonyl group derivatives) to give olefins in an or-ganometallic variation on the “Wittig” reaction. In contrast to this classical procedure which gives phosphine oxide in addition