Olefinic cyclizations promoted by Beckmann rearrangement of oxime sulfonate
Olefinic cyclizations promoted by Beckmann rearrangement of oxime sulfonate
复制标题
肟磺酸盐贝克曼重排促进的烯烃环化
DOI：
10.1021/ja00341a086
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发表时间：
1983
影响因子：
15
通讯作者：
Hisashi Yamamoto
中科院分区：
文献类型：
--
作者：
S. Sakane;Y. Matsumura;Yoshihiro Yamamura;Y. Ishida;K. Maruoka;Hisashi Yamamoto
在本文中，我们报告的合成和表征的五羰基金属酸三阴离子的铌和钽，这是第一个化合物包含这些元素的正式氧化态的-3。虽然其他第二和第三行过渡元素的金属羰基三阴离子也被要求保护，但这些也是第一个被分离为分析纯物质的例子。经常观察到第一行过渡金属与第二和第三行同系物的羰基化学存在实质性差异。例如，当Cr（CO）6容易与Na-NH 3反应以提供高产率的Na 2Cr（CO）5时，M（CO）6（M= Mo，W）的相应还原仅产生非常低产率的热不稳定的Na 2 M（CO）5。3，4。
In this paper we report on the syntheses and characterizations of the pentacarbonylmetallate trianions of niobium and tantalum, which are the first compounds to contain these elements in a formal oxidation state of-3. Although metal carbonyl trianions of other second-and third-row transition elements have been claimed, 2 these are also the first examples to have been isolated as ana-lytically pure substances. Substantial differences in the carbonyl chemistry of first-row transition metals and that of second and third row homologues are often observed. For example, while Cr (CO) 6 readily reacts with Na-NH3 to providehigh yields of Na2Cr (CO) 5, corre-sponding reductions of M (CO) 6 (M= Mo, W) give only very low yields of thermally unstableNa2M (CO) 5.3, 4 For these reasons it was by no means obvious whether reductions of the isoelectronic