Type 2 Intramolecular Nitroso Diels−Alder Reaction. Synthesis and Structure of Bridgehead Oxazinolactams
作者:Steven M. Sparks、Jesse D. Vargas、Kenneth J. Shea
DOI:10.1021/ol005811m
日期:2000.5.1
[reaction--see text] The type 2intramolecular Diels-Alder cycloaddition utilizing N-acylnitroso dienophiles provides an efficient entry into bridged oxazinolactams. In contrast to the bimolecular counterpart, the reaction is completely regioselective. Structural characterization of the cycloadducts allows for evaluation of the olefin distortion and the degree of pyramidalization of the bridgehead
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.
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
Copper(II)-Catalyzed Room Temperature Aerobic Oxidation of Hydroxamic Acids and Hydrazides to Acyl-Nitroso and Azo Intermediates, and Their Diels–Alder Trapping
作者:Duangduan Chaiyaveij、Leah Cleary、Andrei S. Batsanov、Todd B. Marder、Kenneth J. Shea、Andrew Whiting
DOI:10.1021/ol201188d
日期:2011.7.1
2-ethyl-2-oxazoline ligand, is an effective catalyst for the room temperature, aerobicoxidation of hydroxamic acids and hydrazides, to acyl-nitroso and azo dienophiles respectively, which are efficiently trapped in situ via both inter- and intramolecular hetero-Diels–Alder reactions with dienes. Both inter- and intramolecular variants of the Diels–Alder reaction are suitable under the reaction conditions using a variety