Type 2 Intramolecular <i>N</i>-Acylnitroso Diels−Alder Reaction: Scope and Application to the Synthesis of Medium Ring Lactams
作者:Steven M. Sparks、Chun P. Chow、Liang Zhu、Kenneth J. Shea
DOI:10.1021/jo049897z
日期:2004.4.1
Heteroatom variants of the type 2 intramolecularDiels−Alderreaction provide an efficient method for the preparation of bridged bicyclic heterocycles. The type 2 variant of the intramolecular N-acylnitroso Diels−Alderreaction is an effective method for the synthesis of bridged bicyclic oxazinolactams. Structural studies of the cycloadducts have allowed for quantification of the deformations of the
Dual Function Catalysts. Dehydrogenation and Asymmetric Intramolecular Diels−Alder Cycloaddition of <i>N</i>-Hydroxy Formate Esters and Hydroxamic Acids: Evidence for a Ruthenium−Acylnitroso Intermediate
作者:Chun P. Chow、Kenneth J. Shea
DOI:10.1021/ja050059b
日期:2005.3.1
The chiral ruthenium salen complex, 13b, functions as an efficient catalyst for the sequential oxidation and asymmetric Diels-Alder cycloaddition of hydroxamic acids and N-hydroxy formate esters. This result provides evidence for the formation of a ruthenium-nitroso formate (acyl nitroso) intermediate. The Diels-Alder precursors are prepared from simple building blocks, and the cycloadducts, bridged oxazinolactams, can serve as useful intermediates in organic synthesis.