Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization

• Chunhui Dai,
• Bo Liang and
• Corey R. J. Stephenson

Beilstein J. Org. Chem. 2012, 8, 986–993, doi:10.3762/bjoc.8.111

• ; 1,3-dicarbonyl compounds; Diels–Alder reaction; molecular diversity; pyridine dearomatization; spirooxindole; Introduction The spirooxindole is a common structural motif found in a variety of complex alkaloids [1]. Many compounds that possess a spirooxindole moiety exhibit significant biological

• novel and practical methods for the preparation of diverse heterocyclic compounds, herein, we report our extended investigation on the efficient synthesis of spirooxindole [1,3]oxazino derivatives by means of alkylative pyridine dearomatization [18][19][20][21]. Results and Discussion Reactions of N

• established a facile route to our desired vinylogous sulfonyl esters 6, we next examined their reactivity towards alkylative pyridine dearomatization reactions (Table 2). During optimization studies, we discovered that the reaction performed best at 45 °C using pyridine as the solvent. The substituent groups