Organic Synthesis Group, Department of Chemistry, School of Chemical and Biotechnology, SASTRA University , Thanjavur 613 401, Tamil Nadu, India.
Chemical Engineering and Process Development Division, National Chemical Laboratory , Pashan Road, Pune 411 008, India.
Org Lett. 2016 Jul 15;18(14):3442-5. doi: 10.1021/acs.orglett.6b01623. Epub 2016 Jun 29.
A novel palladium-catalyzed hydration-olefin insertion cascade assisted by internal nucleophiles was developed for the synthesis of biologically significant 2,3-dihydro-1H-inden-1-ones under mild conditions. A detailed mechanistic study revealed that the assistance of the internal nucleophiles is crucial to trigger the cascade reaction via nucleopalladation of the alkyne moiety. The overall reaction is equivalent to regioselective hydration of alkynes followed by intramolecular Michael addition. This highly efficient and 100% atom-economical domino sequence afforded cis-2,3-disubstituted 2,3-dihydro-1H-inden-1-ones in excellent yields (up to 99%) with complete diastereoselectivity.
一种新的钯催化的水合-烯烃插入级联反应被开发出来，该反应在温和条件下，以内源性亲核试剂辅助，用于合成具有生物意义的 2,3-二氢-1H-茚-1-酮。详细的机理研究表明，内源性亲核试剂的辅助对于通过炔烃部分的亲核钯化触发级联反应至关重要。整个反应相当于炔烃的区域选择性水合，然后是分子内迈克尔加成。这种高效且 100%原子经济性的多米诺序列以优异的收率（高达 99%）和完全的非对映选择性提供了顺式-2,3-二取代的 2,3-二氢-1H-茚-1-酮。
