Siloxyalkyne–Alkene Metathesis: Rapid Access to Highly Functionalized Enones
摘要:
Mechanistically intriguing participation of siloxyalkynes occurs in the intramolecular Ru-catalyzed metathesis with terminal alkenes (see scheme; Ms=methanesulfonyl). Combined with efficient protodesilylation, this process resulted in the development of a new method for the synthesis of highly functionalized enones starting from readily accessible acyclic precursors. Heterocyclic and polycyclic compounds were prepared efficiently, which illustrates the generality of this novel method.
Siloxyalkyne–Alkene Metathesis: Rapid Access to Highly Functionalized Enones
摘要:
Mechanistically intriguing participation of siloxyalkynes occurs in the intramolecular Ru-catalyzed metathesis with terminal alkenes (see scheme; Ms=methanesulfonyl). Combined with efficient protodesilylation, this process resulted in the development of a new method for the synthesis of highly functionalized enones starting from readily accessible acyclic precursors. Heterocyclic and polycyclic compounds were prepared efficiently, which illustrates the generality of this novel method.
A New Approach to the Nazarov Reaction via Sequential Electrocyclic Ring Opening and Ring Closure
作者:Tina N. Grant、F. G. West
DOI:10.1021/ja063421a
日期:2006.7.1
furnishes vinylcyclopropanol silyl ethers in good yield. Treatment with silver(I) at room temperature effects disrotatory electrocyclic opening to a 2-chloro-3-silyloxypentadienyl cation, which then undergoes conrotatory (Nazarov) electrocyclization to provide chlorocyclopentenones. This two-step sequence offers a convenient and mild alternative to the standard Nazarovcyclization protocol via a formal 4+1
Reversal of the Regiochemistry in the Rhodium-Catalyzed [4+3] Cycloaddition between Vinyldiazoacetates and Dienes
作者:Pablo E. Guzmán、Yajing Lian、Huw M. L. Davies
DOI:10.1002/anie.201406440
日期:2014.11.24
regio‐, diastereo‐, and enantioselective [4+3] cycloadditionbetween vinylcarbenes and dienes has been achieved using the dirhodium tetracarboxylate catalyst [Rh2(S‐BTPCP)4]. This methodology provides facile access to 1,4‐cycloheptadienes that are regioisomers of those formed from the tandem cyclopropanation/Cope rearrangement reaction of vinylcarbenes with dienes.
Mechanistically intriguing participation of siloxyalkynes occurs in the intramolecular Ru-catalyzed metathesis with terminal alkenes (see scheme; Ms=methanesulfonyl). Combined with efficient protodesilylation, this process resulted in the development of a new method for the synthesis of highly functionalized enones starting from readily accessible acyclic precursors. Heterocyclic and polycyclic compounds were prepared efficiently, which illustrates the generality of this novel method.