Triflimide-catalysed sigmatropic rearrangement of N-allylhydrazones as an example of a traceless bond construction
作者:Devon A. Mundal、Christopher T. Avetta、Regan J. Thomson
DOI:10.1038/nchem.576
日期:2010.4
The recognition of structural elements (that is, retrons) that signal the application of specific chemical transformations is a key cognitive event in the design of synthetic routes to complex molecules. Reactions that produce compounds without an easily identifiable retron, by way of either substantial structural rearrangement or loss of the atoms required for the reaction to proceed, are significantly more difficult to apply during retrosynthetic planning, yet allow for non-traditional pathways that may facilitate efficient acquisition of the target molecule. We have developed a triflimide (Tf2NH)-catalysed rearrangement of N-allylhydrazones that allows for the generation of a sigma bond between two unfunctionalized sp3 carbons in such a way that no clear retron for the reaction remains. This new âtracelessâ bond construction displays a broad substrate profile and should open avenues for synthesizing complex molecules using non-traditional disconnections. A triflimide-catalysed rearrangement of N-allylhydrazones has been developed that allows for the generation of a sigma bond between two unfunctionalized sp3 carbons such that no clear marker remains for how the bond was formed. This traceless bond construction offers new avenues for convergent fragment coupling in synthetic strategies.
在设计复杂分子的合成路线时,识别结构元素(即逆反应)是应用特定化学转化的关键认知活动。通过大量的结构重排或失去反应进行所需的原子而生成的化合物没有易于识别的重排元素,这种反应在逆合成规划中的应用要困难得多,但却允许通过非传统途径来促进目标分子的高效获取。我们开发了一种由三氟利昂(Tf2NH)催化的 N-烯丙基肼重排反应,它可以在两个未官能化的 sp3 碳之间生成一个西格玛键,从而使反应不再需要明确的重排原子。这种新的 "无痕 "键构造具有广泛的底物特征,为利用非传统断开方式合成复杂分子开辟了道路。我们开发出了一种由三氟甲基甲酰亚胺催化的 N-烯丙基肼重排反应,这种反应可以在两个未官能化的 sp3 碳之间生成一个西格玛键,而且不会留下键是如何形成的明确标记。这种无痕键的构建为合成策略中的聚合片段偶联提供了新的途径。