J Am Chem Soc. 2015 Apr 29;137(16):5316-9. doi: 10.1021/jacs.5b02280. Epub 2015 Apr 15.
Generation of reactive α-oxo gold carbene intermediates via gold-catalyzed oxidation of alkynes has become an increasing versatile strategy of replacing hazardous diazo carbonyl compounds with benign and readily available alkynes in the development of efficient synthetic methods. However, one of the hallmarks of metal carbene/carbenoid chemistry, i.e., insertion into an unactivated C(sp(3))-H bond, has not be realized. This study reveals for the first time that this highly valuable transformation can be readily realized intramolecularly by oxidatively generated β-diketone-α-gold carbenes using ynones as substrates. Substrate conformation control via the Thorpe-Ingold effect is the key design feature that enables generally good to excellent efficiencies, and synthetically versatile cyclopentanones including spiro-, bridged, and fused bicyclic ones can be readily accessed.
通过金催化炔烃的氧化生成反应性α-氧代金卡宾中间体已成为一种越来越多的替代危险重氮羰基化合物的策略，用良性且易于获得的炔烃取代它们，从而开发有效的合成方法。然而，金属卡宾/卡宾型化合物化学的一个特点，即插入非活化的 C(sp(3))-H 键，尚未实现。这项研究首次揭示了这一非常有价值的转化可以通过使用炔酮作为底物，通过氧化生成的β-二酮-α-金卡宾中间体在分子内轻易地实现。通过 Thorpe-Ingold 效应进行的底物构象控制是关键的设计特点，它可以实现通常良好到优秀的效率，并且可以轻易地获得包括螺环、桥环和稠合双环在内的具有合成多功能性的环戊酮。
