Efficient Nazarov Cyclization/Wagner-Meerwein Rearrangement Terminated by a Cu<sup>II</sup>-Promoted Oxidation: Synthesis of 4-Alkylidene Cyclopentenones
作者:David Lebœuf、Eric Theiste、Vincent Gandon、Stephanie L. Daifuku、Michael L. Neidig、Alison J. Frontier
DOI:10.1002/chem.201203396
日期:2013.4.8
The discovery and elucidation of a new Nazarovcyclization/Wagner–Meerweinrearrangement/oxidation sequence is described that constitutes an efficient strategy for the synthesis of 4‐alkylidene cyclopentenones. DFT computations and EPR experiments were conducted to gain further mechanistic insight into the reaction pathways.
Experimental and Theoretical Studies on the Nazarov Cyclization/Wagner–Meerwein Rearrangement Sequence
作者:David Lebœuf、Vincent Gandon、Jennifer Ciesielski、Alison J. Frontier
DOI:10.1021/ja211970p
日期:2012.4.11
Highly functionalizedcyclopentenones can be generated by a chemoselective copper(II)-mediated Nazarov/Wagner-Meerwein rearrangement sequence of divinyl ketones. A detailed investigation of this sequence is described including a study of substrate scope and limitations. After the initial 4π electrocyclization, this reaction proceeds via two different sequential [1,2]-shifts, with selectivity that depends
Using Nazarov Electrocyclization to Stage Chemoselective [1,2]-Migrations: Stereoselective Synthesis of Functionalized Cyclopentenones
作者:David Lebœuf、Jie Huang、Vincent Gandon、Alison J. Frontier
DOI:10.1002/anie.201104870
日期:2011.11.11
Highly functionalizedcyclopentenones have been prepared stereospecifically through a chemoselective copper(II)‐mediated Nazarov/Wagner–Meerwein rearrangement sequence. After the initial 4π electrocyclization, this reaction involves two sequential [1,2]‐migrations depending upon both migratory ability and steric bulk of the substituents at C1 and C5 (see scheme). The proposed mechanism of the reaction
Reagent Control of [1,2]-Wagner-Meerwein Shift Chemoselectivity Following the Nazarov Cyclization: Application to the Total Synthesis of Enokipodin B
作者:David Lebœuf、Christopher M. Wright、Alison J. Frontier
DOI:10.1002/chem.201203395
日期:2013.4.8
carbon framework of various sesquiterpenes from the herbertane and cuparane families is described, including the concise total synthesis of enokipodin B. The key step is the construction of the vicinal quarternary centers of the skeleton through a tandem Nazarovcyclization/Wagner–Meerwein rearrangement mediated by a copper(II) complex. During this study, it was also found that changing the ligand architecture