Chiral oxygenated aliphatic moieties are recurrent in biological and pharmaceutically relevant molecules and constitute one of the most versatile types of functionalities for further elaboration. Herein we report a protocol for straightforward and general access to chiral γ-lactones via enantioselective oxidation of strong nonactivated primary and secondary C(sp3)–H bonds in readily available carboxylic
A direct conversion of C(sp(3))-H bonds to C(sp3)-N bonds has been achieved by utilizing catalytic N-hydroxyphthalimide (NHPI) and stoichiometric dialkyl azodicarboxylate. NHPI functions as a precursor of the electron-deficient phthalimide N-oxyl radical (PINO) to abstract hydrogens, and dialkyl azodicarboxylate acts as a trapping agent of the resultant carbon radical to generate the hydrazine derivatives. This C-H amination proceeds in a highly chemoselective manner with a wide applicability to functionalize benzylic, propargylic, and aliphatic C-H bonds. Furthermore, the obtained hydrazine compounds were readily converted to the corresponding carbamates or amines. Hence, the present protocol for direct introduction of the nitrogen functionality serves as a powerful tool for efficient construction of nitrogen-substituted natural products and pharmaceuticals.
Carbonylation of aliphatic and cyclic alcohols by carbon monoxide in the presence of complexes of BF3 with acetic, propionic, or monochloroacetic acid
作者:S. D. Pirozhkov、K. V. Puzitskii、T. N. Myshenkova、K. G. Ryabova、Ya. T. �idus
DOI:10.1007/bf01108192
日期:1977.4
Koch; Haaf, Justus Liebigs Annalen der Chemie, 1958, vol. 618, p. 251,261