Efficient Synthesis of Polysubstituted 1,5-Benzodiazepinone Dipeptide Mimetics via an Ugi-4CR-Ullmann Condensation Sequence
作者:Robin Van Den Hauwe、Mathias Elsocht、Steven Ballet、Charlie Hollanders
DOI:10.1055/a-1545-2860
日期:2021.10
three-step synthesis towards 3-amino-1,4-benzodiazepin-2-one derivatives is presented. The versatile Ugi-4-component reaction (Ugi-4CR) and Boc deprotection is followed by a ligand-free Ullmann condensation. This protocol allows the rapid construction of a diverse array of substituted 1,5-benzodiazepinones. Since Ugi-based products are typically limited by their ‘inert’ C-terminal amides, the use of a convertible
Environmentally friendly TPDS-mediated free radical ring expansion of α-haloalkyl cyclic β-keto esters
作者:Masaaki Sugi、Hideo Togo
DOI:10.1016/s0040-4020(02)00241-7
日期:2002.4
Reactivities of tetraphenyldisilane (TPDS), tris(trimethylsilyl)silane, and tributyltin hydride in the radicalringexpansion of α-haloalkyl cyclic β-keto esters were examined. Among these reagents, TPDS was found most effective for the preparation of medium-sized cyclic compounds in terms of yields and ring-expansion/reduction selectivity.
Iron-Catalyzed C(sp3)–H Alkylation through Ligand-to-Metal Charge Transfer
作者:Tomislav Rovis、Yi Cheng Kang、Sean M. Treacy
DOI:10.1055/s-0040-1720388
日期:2021.10
FeCl3-catalyzed alkylation of nonactivated C(sp3)–H bonds. Photoinduced ligand-to-metal charge transfer at the iron center generates chlorine radicals that then preferentially abstract hydrogen atoms from electron-rich C(sp3)–H bonds distal to electron-withdrawing functional groups. The resultant alkyl radicals are trapped by electron-deficient olefins, and the catalytic cycle is closed by Fe(II) recombination