Cameron Lisa L, Wang Sheila C, Kluger Ronald
Davenport Chemistry Research Building, Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
J Am Chem Soc. 2004 Sep 1;126(34):10721-6. doi: 10.1021/ja049538l.
The direct monoacylation of diols by acyl phosphate monoesters in water is a biomimetic analogy to the enzymic aminoacylation of tRNA by aminoacyl adenylates. Without catalysis, acyl phosphate monoesters react rapidly with amines but very slowly with water and alcohols. Lanthanide ions dramatically and selectively facilitate the base-catalyzed monoacylation of diols in water by methyl benzoyl phosphate (MBP), a typical acyl phosphate monoester, in neutral solutions where reactive amines are protonated and unreactive. The reaction patterns and reactivity of various diols with MBP in the presence of lanthanides are consistent with a mechanism that involves internal addition from the conjugate base of the bis-bidentate complex of the lanthanide with the diol and MBP. The method is also applicable to reactions of nucleosides as evidenced by the selective monoacylation of the 2'- or 3'-hydroxyl group of adenosine, without reaction of the 5'-hydroxyl group or the 6-amino group. Analogues of adenosine without the diol are unreactive. This suggests that the method will selectively monoacylate the hydroxyl groups at the unique diol in tRNA that forms the 3'-terminus.
水中酰基磷酸单酯对二醇的直接单酰化反应是一种与氨基酰腺苷酸对tRNA进行酶促氨基酰化反应类似的仿生反应。在没有催化作用的情况下，酰基磷酸单酯与胺反应迅速，但与水和醇反应非常缓慢。镧系离子能显著且选择性地促进在中性溶液中，典型的酰基磷酸单酯——苯甲酰磷酸甲酯（MBP）对二醇进行碱催化的单酰化反应，在这种中性溶液中，活性胺已质子化且无反应活性。在镧系元素存在下，各种二醇与MBP的反应模式和反应活性与一种机制相符，该机制涉及镧系元素与二醇和MBP的双齿配合物的共轭碱的内部加成。该方法也适用于核苷的反应，如腺苷的2'-或3'-羟基的选择性单酰化反应可证明这一点，而5'-羟基或6-氨基不发生反应。没有二醇的腺苷类似物无反应活性。这表明该方法将选择性地对tRNA中形成3'-末端的独特二醇处的羟基进行单酰化。
