Sequentially rhodium-catalyzed enantioselective cycloisomerization–hydrogenation syntheses of alkylidene butyrolactone β-hydroxyethanes and alkylidene tetrahydrofuran β-aminoethanes
作者:Nadine Muschelknautz、Frank Rominger、Thomas J. J. Müller
DOI:10.1007/s10593-018-2267-1
日期:2018.3
and ether-tethered alkyne allyl alcohols is an excellent entry to subsequent Rh-catalyzed one-pot hydrogenations in the sense of sequentially Rh-catalyzed processes to chiral alkylidene butyrolactone β-hydroxyethanes and alkylidene tetrahydrofuran β-aminoethanes, respectively, with excellent levels of enantioselectivity.
A Highly Reusable Rhodium Catalyst-Organic Framework for the Intramolecular Cycloisomerization of 1,6-Enynes
作者:Elizabeth G. Corkum、Michael J. Hass、Andrew D. Sullivan、Steven H. Bergens
DOI:10.1021/ol201333s
日期:2011.7.1
The intramolecular cycloisomerization of 1,6-enynes in 95-99% ee is reported using an immobilized Rh catalyst-organic framework synthesized from alternating ring-opening metathesis polymerization (altROMP) assembly. The framework was reused up to seven times, and it was used in high turnover number (TON) batch reactions. The catalyst provided the highest TONs to date (up to 890) for the cycloisomerizations, with catalyst loadings ranging from 0.2 to 0.06 mol %.