Metal-free, hydroacylation of CC and NN bonds via aerobic C–H activation of aldehydes, and reaction of the products thereof
作者:Vijay Chudasama、Ahmed R. Akhbar、Karim A. Bahou、Richard J. Fitzmaurice、Stephen Caddick
DOI:10.1039/c3ob41632a
日期:——
In this report, a thorough evaluation of the use of aerobically initiated, metal-free hydroacylation of various CC and NN acceptor molecules with a wide range of aldehydes is presented. The aerobic-activation conditions that have been developed are in sharp contrast to previous conditions for hydroacylation, which tend to use transition metals, peroxides that require thermal or photochemical degradation, or N-heterocyclic carbenes. The mildness of the conditions enables a number of reactions involving sensitive reaction partners and, perhaps most significantly, allows for α-functionalised chiral aldehydes to undergo radical-based hydroacylation with complete retention of optical purity. We also demonstrate how the resulting hydroacylation products can be transformed into other useful intermediates, such as γ-keto-sulfonamides, sultams, sultones, cyclic N-sulfonyl imines and amides.
在本报告中,我们详细评估了使用需氧起始、不含金属的氢酰化方法,将多种CC和NN受体分子与广泛范围的醛进行反应的情况。我们所开发的有氧活化条件与之前的氢酰化条件形成鲜明对比,后者倾向于使用过渡金属、需要热或光化学分解的过氧化物,或者N-杂环卡宾。这些温和的条件使得许多涉及敏感反应物的反应得以进行,或许最为重要的是,能够让α-功能化的手性醛在基于自由基的氢酰化反应中完全保持光学纯度。我们还展示了所得氢酰化产物如何转化成其他有用的中间体,例如γ-酮-磺酰胺、磺内酰胺、磺内酯、环状N-磺酰亚胺和酰胺。