Catalytic Asymmetric Formation of δ-Lactones from Unsaturated Acyl Halides
作者:Paolo S. Tiseni、René Peters
DOI:10.1002/chem.200902896
日期:2010.2.22
Previously unexplored enantiopure zwitterionic ammonium dienolates have been utilized in this work as reactive intermediates that act as diene components in hetero‐Diels–Alderreactions (HDAs) with aldehydes to produce optically active δ‐lactones, subunits of numerous bioactive products. The dienolates were generated in situ from E/Z mixtures of α,β‐unsaturated acid chlorides by use of a nucleophilic
Lewis Acid−Lewis Base Catalyzed Enantioselective Hetero-Diels−Alder Reaction for Direct Access to δ-Lactones
作者:Paolo S. Tiseni、René Peters
DOI:10.1021/ol800742d
日期:2008.5.1
unprecedented [4 + 2] cycloaddition of alpha,beta-unsaturated acid chlorides with a broad range of aromatic and heteroaromatic aldehydes by a cooperative bifunctional Lewisacid-Lewis base catalytic mode of action providing valuable delta-lactone building blocks with excellent enantioselectivity.
Switchable Diastereoselectivity in Enantioselective [4+2] Cycloadditions with Simple Olefins by Asymmetric Binary Acid Catalysis
作者:Jian Lv、Long Zhang、Sanzhong Luo、Jin-Pei Cheng
DOI:10.1002/anie.201304561
日期:2013.9.9
The exchange of the metal ion from InIII to ScIII in a binary acid catalyst leads to a switch in the diastereoselectivity of [4+2] cycloadditions. Simpleolefins and β,γ‐unsaturated α‐ketoester were thus transformed to the corresponding exo or endo products, respectively, with excellent diastereoselectivity (up to 99:1 d.r.) and enantioselectivity (up to 99 % ee).