2006

Multi-membered O,S-heterocyclesR 0691 Cyclocarbopalladation of Alkynes: A Stereoselective Method for Preparing

Dibenzoxapine Containing Tetrasubstituted Exocyclic Alkenes. — The palladium--catalyzed intramolecular alkyne carbometalation reaction with different boronic acids affords the desired dibenzoxepin derivatives (III) and (V) with high stereo- and regio-control. Employing phosphine-free Pd(0) catalyst and water as the cosolvent, the target compounds are obtained in excellent yields. Tetrasubstituted dibenzoxazepines such as (IIIg), interesting in pharmaceutical industry, can be prepared by selective reduction of the nitro group in (IIIa). — (YU*, H.; RICHEY, R. N.; CARSON, M. W.; COGHLAN, M. J.; Org. Lett. 8 (2006) 8, 1685-1688; Lilly Res. Lab., Chem. Prod. Res. Dev., Eli Lilly Co., Lilly Corp. Cent., Indianapolis, IN 46285, USA; Eng.) — Bartels

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