A Robust Protocol for the Synthesis of Quinoxalines and 5H-Benzo[e][1,4]diazepines via the Acidless Ugi Reaction
摘要:
Concise two-step, one-pot protocols for the syntheses of quinoxalines and 5H-benzo[e][1,4]diazepines are reported. An acidless' Ugi reaction followed by a Boc-deprotection-cyclization sequence is shown to produce arrays of both functionalized scaffolds in good yield. Mono-N-Boc-protected diamines are employed to access quinoxalines and an analogous benzylic amine affords access to 5H-benzo[e][1,4]diazepines in conjunction with supporting reagents in the acidless' Ugi reaction. Both methodologies are robust, straightforward, and allow installation of at least three points of diversity in the resulting scaffolds.
Concise two-step, one-pot protocols for the syntheses of quinoxalines and 5H-benzo[e][1,4]diazepines are reported. An acidless' Ugi reaction followed by a Boc-deprotection-cyclization sequence is shown to produce arrays of both functionalized scaffolds in good yield. Mono-N-Boc-protected diamines are employed to access quinoxalines and an analogous benzylic amine affords access to 5H-benzo[e][1,4]diazepines in conjunction with supporting reagents in the acidless' Ugi reaction. Both methodologies are robust, straightforward, and allow installation of at least three points of diversity in the resulting scaffolds.