Thermal <i>Hetero</i>-Diels–Alder Reaction of Benzocyclobutenones with Isatins To Form 2-Oxindole Spirolactones
作者:Thomas Wurm、Ben W. H. Turnbull、Brett R. Ambler、Michael J. Krische
DOI:10.1021/acs.joc.7b02769
日期:2017.12.15
or “ortho-quinoid ketene methides”, which engage in intermolecular [4+2] cycloadditions with isatins 2a–2f to form 2-oxindole spirolactones 3a–3l. This process tolerates an array of different functional groups and substitution patterns, and is applicable to unprotected isatins 2b–2f bearing free NH-functionalities. The superior performance of isatins compared to other carbonyl based dienophiles was