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[reaction: see text] A palladium-catalyzed regioselective C-H bond functionalization driven by CO as the stoichiometric reductant is described. Nitrogen heterocycles, e.g., carbazoles, are accessible in good to excellent yields with use of palladium acetate and 70 psig of carbon monoxide at 140 degrees C.

During investigations of the basic reactivity of siliranes, Seyferth observed that hexamethylsilirane (1) undergoes insertion of aldehydes to afford oxasilacyclopentane 2 (eq l).1•2 345678Since this silirane was the only one examined, the stereochemistry and regiochemistry of this carbon-carbon bond-forming process have not been investigated, although this information would provide vital clues about the reaction mechanism. In fact, little is known about the scope of silirane chemistry.2-8 We have discovered that siliranes undergo stereochemically and regiochemically defined insertions of aldehydes, and the outcome is determined by the reaction conditions. Furthermore, siliranes were used for the synthesis of diols such as 4 in two steps (aldehyde insertion and oxidation) from the silirane trans-3, which can be obtained by silacyclopropanation of (£>2-butene (eq 2).9

[reaction: see text] A number of approaches for the synthesis of the 1H-indol-2-yl-1H-quinolin-2-one ring system found in the potent and selective KDR kinase inhibitor 1 are described. The preparation and reaction of trimethylsilylnitrobenzene 26 with 2-methoxy-3-quinolinecarboxaldehyde 28 afforded alcohol 30, which was the key intermediate for the preparation of the target compounds. Conversion of alcohol 30 to either nitroketone 36 or nitrostyrene 45 set the stage for reductive cyclization and the formation of indole 25. The quinolin-2-one functionality was unmasked in the last step to provide compound 1 in 56-60% overall yield from readily available starting materials.