Nazarov Reactions Intercepted by (4 + 3) Cycloadditions with Oxygen-Substituted Dienes
作者:François M. LeFort、Vinayak Mishra、Graham D. Dexter、Timothy D. R. Morgan、D. Jean Burnell
DOI:10.1021/acs.joc.5b00914
日期:2015.6.5
The oxyallyl cation intermediate from the Lewisacidmediated Nazarov reaction of an allenyl vinyl ketone was intercepted by acyclic, 2-silyloxy-substituted butadienes by highly regioselective (4 + 3) cycloadditions. Stereoselectivity was often modest, but in some instances steric interactions were responsible for high selectivity. The results are consistent with concerted (4 + 3) cycloadditions. In
Enantioselective Organocatalytic Singly Occupied Molecular Orbital Activation: The Enantioselective α-Enolation of Aldehydes
作者:Hye-Young Jang、Jun-Bae Hong、David W. C. MacMillan
DOI:10.1021/ja0719428
日期:2007.6.6
e products with uniformly high levels of asymmetric induction. Wide latitude in both the aldehyde and enolsilane component is readily accommodated, allowing generic access to a diverse assortment of enantioenriched 1,4-dicarbonyl compounds. This report highlights the potential of SOMO catalysis to enable the development of entirely new classes of asymmetric reactions that have no traditional catalytic
The clerodane ring system: investigating the viability of a direct Diels–Alder approach
作者:Andrew T. Merritt、Rebecca H. Pouwer、David J. Williams、Craig M. Williams、Steven V. Ley
DOI:10.1039/c1ob05422h
日期:——
A direct synthetic approach to the spiro-γ-lactone clerodane ring system has been investigated. This work builds on that of Jung and highlights the inherent difficulties associated with the otherwise obvious Diels–Alderapproach.
Control of the Regio- and Stereoselectivity in Diels-Alder Reactions with Quinone Boronic Acids
作者:María C. Redondo、Marcos Veguillas、María Ribagorda、M. Carmen Carreño
DOI:10.1002/anie.200803428
日期:2009.1.2
The dienophilic reactivity of 2‐methyl‐substituted quinones has been substantially increased by the introduction of a boronicacid substituent, which makes them equivalent to a highly reactive quinone. The Diels–Alderreactions of these quinones are followed by spontaneous and stereoselective protodeboronation to give the trans‐fused adducts. The boron group is a temporal regiocontroller and leads to
Enantioselective Formal Total Synthesis of (−)-Dysidiolide
作者:Michael E. Jung、Nobuko Nishimura
DOI:10.1021/ol016073k
日期:2001.6.1
[reaction: see text] An enantioselective formal totalsynthesis of the sesterterpene (-)-dysidiolide 1 beginning with an intermolecular Diels-Alder reaction of the allene ester 3 and the silyloxydiene 10 is reported.