Green Chemical Synthesis of 2-Benzenesulfonyl-pyridine and Related Derivatives
作者:William G. Trankle、Michael E. Kopach
DOI:10.1021/op700060e
日期:2007.9.1
A practical synthesis of 2-benzenesulfonylpyridine, 1, is described which is a key starting material for the manufacture of an investigational new drug candidate at Eli Lilly and Company. An optimized green chemical process was developed which features a novel tandem SNAr/oxidation under mild conditions to produce the target sulfone, 1, in 86% yield and >99% purity. In addition, this novel, environmentally friendly methodology was found to be general for the synthesis of substituted aromatic pyridyl sulfides and sulfones.
Palladium-catalyzed heteroaryl thioethers synthesis overcoming palladium dithiolate resting states inertness: Practical road to sulfones and NH-sulfoximines
provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium–1,1′-bis[(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance
We describe an efficient palladium‐catalyzed selective C–H ortho‐monohalogenation (X=I, Br, Cl, F) of various functionalized (2‐pyridyl)arylsulfones. ortho‐, meta‐ and para‐functionalization is tolerated at the arene group which undergoes C–H halogenation. Some modifications are also possible on the 2‐(arylsulfonyl)heteroaryl directing groups. A comparison of the halogenation efficiency suggests that