2402-96-2Relevant articles and documents
Visible-Light-Induced ortho-Selective Migration on Pyridyl Ring: Trifluoromethylative Pyridylation of Unactivated Alkenes
Jeon, Jinwon,He, Yu-Tao,Shin, Sanghoon,Hong, Sungwoo
supporting information, p. 281 - 285 (2019/11/26)
The photocatalyzed ortho-selective migration on a pyridyl ring has been achieved for the site-selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho-position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well-suited for addition to the C2-position of pyridinium salts to ultimately provide synthetically valuable C2-fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P-centered radicals. The utility of this transformation was further demonstrated by the late-stage functionalization of complex bioactive molecules.
Hydroheteroarylation of Unactivated Alkenes Using N-Methoxyheteroarenium Salts
Ma, Xiaoshen,Dang, Hester,Rose, John A.,Rablen, Paul,Herzon, Seth B.
supporting information, p. 5998 - 6007 (2017/05/04)
We report the first reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%). N-Methoxy imidazolium salts are accessible in three steps from commercial amines (50-85%). In total 36 discrete methoxyheteroarenium salts bearing electron-donating, electron-withdrawing, alkyl, aryl, halogen, and haloalkyl substituents were prepared (several in multigram quantities) and coupled with 38 different alkenes. The transformations proceed under neutral conditions at ambient temperature, provide monoalkylation products exclusively, and form a single alkene addition regioisomer. Preparatively useful and complementary site selectivities in the addition of secondary and tertiary radicals to pyidinium salts are documented: harder secondary radicals favor C-2 addition (2->10:1), while softer tertiary radicals favor bond formation to C-4 (4.7->29:1). A diene possessing a 1,2-disubstituted and 2,2-disubstituted alkene undergoes hydropyridylation at the latter exclusively (61%) suggesting useful site selectivities can be obtained in polyene substrates. The methoxypyridinium salts can also be employed in dehydrogenative arylation, borono-Minisci, and tandem arylation processes. Mechanistic studies support the involvement of a radical process.
BRIDGED, BICYCLIC HETEROCYCLIC OR SPIRO BICYCLIC HETEROCYCLIC DERIVATIVES OF PYRAZOLO[1,5-A]PYRIMIDINES, METHODS FOR PREPARATION AND USES THEREOF
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Page/Page column 38, (2009/10/21)
Compounds of formula A: Formula (1) pharmaceutically acceptable salts thereof are described, which selectively inhibit Raf kinase activity and are useful for treating disorders mediated by Raf kinases.