Díaz-Oltra Santiago, Carda Miguel, Murga Juan, Falomir Eva, Marco J Alberto
Department de Q. Inorgánica y Orgánica, University Jaume I, Avda. Sos Baynat s/n, 12071 Castellón, Spain.
Chemistry. 2008;14(30):9240-54. doi: 10.1002/chem.200800956.
Both matched and mismatched diastereoselection have been observed in aldol reactions of a boron enolate of a protected L-erythrulose derivative with several chiral alpha-fluoro and alpha-amino aldehydes. Strict adherence to the Felkin-Anh model for the respective transition structures does not account satisfactorily for all the observed results, as previously observed in the case of alpha-oxygenated aldehydes. In some cases, only the Cornforth model provides a good explanation. The factors that influence this dichotomy are discussed and a general mechanistic model is proposed for aldol reactions with alpha-heteroatom-substituted aldehydes. Additional support for the model was obtained from density functional calculations.
在一种受保护的L-赤藓酮衍生物的硼烯醇化物与几种手性α-氟代和α-氨基醛的羟醛反应中，均观察到了匹配和不匹配的非对映选择性。与之前在α-氧化醛的情况中所观察到的一样，严格遵循各自过渡结构的费尔金-安模型并不能令人满意地解释所有观察结果。在某些情况下，只有康福思模型能给出很好的解释。本文讨论了影响这种二分法的因素，并提出了一个用于α-杂原子取代醛的羟醛反应的通用机理模型。通过密度泛函计算获得了对该模型的额外支持。
