Unusual dirhodium tetraacetate catalyzed intramolecular cyclization of isoquinoline diazoamides
摘要:
The dirhodium(II) tetraacetate catalyzed decomposition of an isoquinoline diazoamide leads to the unexpected formation of a 1,3-oxazin-4-one ring which is consistent with a rare example of an intramolecular metal-carbene hydride-abstraction mechanism. (C) 1999 Elsevier Science Ltd. All rights reserved.
Unusual dirhodium tetraacetate catalyzed intramolecular cyclization of isoquinoline diazoamides
摘要:
The dirhodium(II) tetraacetate catalyzed decomposition of an isoquinoline diazoamide leads to the unexpected formation of a 1,3-oxazin-4-one ring which is consistent with a rare example of an intramolecular metal-carbene hydride-abstraction mechanism. (C) 1999 Elsevier Science Ltd. All rights reserved.
The ability to undergo [4 + 2] versus [2 + 2] cycloaddition was under investigation for ketenes thermally generated from carbamoyl Meldrum's acid. Usually, 1,3‐oxazino‐5‐carbamoylo‐4,6‐diones are formed when carbamoyl Meldrum's acid reacts with imine. However, in some cases, a reaction takes an unexpected course, leading to the formation of tetraponerines alkaloids derivatives or cyclic iminoethers.