Coupling of Aromatic Aldehydes with CO2Me-Substituted TpMe2Ir(III) Metallacyclopentadienes
Coupling of Aromatic Aldehydes with CO2Me-Substituted TpMe2Ir(III) Metallacyclopentadienes
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DOI：
10.1021/om3000554
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发表时间：
2012-03
期刊：
影响因子：
2.8
通讯作者：
Arián E Roa;Verónica Salazar;J. López‐Serrano;E. Oñate;J. Alvarado-Rodríguez;M. Paneque;M. L. Poveda
中科院分区：
文献类型：
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作者：
Arián E Roa;Verónica Salazar;J. López‐Serrano;E. Oñate;J. Alvarado-Rodríguez;M. Paneque;M. L. Poveda
在90-120 °C下，完全CO2 Me取代的水-三氮杂环戊二烯1与各种芳族醛反应，形成双环Fischer型卡宾，其通过将双氢原子转移到金属乳糖的α碳上并伴随O原子与相邻β碳键合而产生。这些碳烯具有这些C-H和C-O键的化学上有利的反构型，但有人提出，未观察到的顺式碳烯是动力学初级产物，其然后容易被外来水差向异构化。温和的反应条件（25-60 °C）允许分离中间体0-配位的醛加合物。虽然这些反应已被观察到的各种芳族醛，2-吡啶甲醛的行为不同，因为该反应导致一个非常稳定的N加合物，尽管两个异构体的O-键合的加合物形成的动力学产物。
The fully CO2Me substituted aquo-iridacyclopentadiene 1 reacts with a variety of aromatic aldehydes, at 90–120 °C, with the formation of bicyclic Fischer-type carbenes, generated by the transfer of the aldehydic H atom to an α carbon of the metallacycle and concomitant bonding of the O atom to the adjacent β carbon. These carbenes have a thermodynamically favored anti configuration of these C–H and C–O bonds but it is proposed that an unobserved syn carbene is the kinetic primary product, which then easily epimerizes by adventitious water. Milder reaction conditions (25–60 °C) allow for the isolation of intermediate O-coordinated aldehyde adducts. While these reactions have been observed for a wide variety of aromatic aldehydes, 2-pyridinecarboxaldehyde behaves differently, as the reaction leads to a very stable N adduct, in spite of two isomeric O-bonded adducts being formed as kinetic products.