Catalytic Cyclization/Silylation of Dienes Containing 1,1-Disubstituted Olefins Using Organolanthanide and Group 3 Organometallic Complexes
摘要:
The catalytic cyclization/silylation reaction of hindered dienes has been investigated using the relatively unhindered complexes Me2Si(C5H3SiMe3)(2)YCH(TMS)(2) and [Cp(2)(TMS)LnMe](2) (Ln = Y, Lu). A nide variety of dienes and trienes bearing a number of functional groups were cyclized, affording silanes containing quaternary centers in a diastereoselective fashion and in good yield. The products can be oxidized using one of several different protocols, yielding alcohols for further functionalization.
Free radical annulation of dichlorocyclobutanones with sequential ring expansion
作者:Paul Dowd、Wei Zhang、Steven J. Geib
DOI:10.1016/0040-4020(95)00093-n
日期:1995.3
reaction of dichloroketene with 1,5-dienes undergo intramolecular freeradical annulation. Lewis acid-promoted ring-opening of the cyclized cyclobutanones then yields novel ringexpansion products. Reaction of (R)-carvone provides an unusual example leading to the formation of a tricyclic dione. The carbonyl group of carvone enhances the radical cyclization and influences the ring-opening pathway.
The carbocyclization of non‐conjugated dienesmediated by organometallics is an important reaction for the synthesis of a variety of carbocyclic derivatives, but the direct annulation of dienes with an inert C−H bond of a substrate has remained unexplored to date. We herein report a series of novel rare‐earth dialkyl complexes bearing a phosphinoamide anion and demonstrate that the combination of a
Sequential cyclization-silylation reactions of 1,1-disubstituted alkenes catalyzed by a cationic zirconocene complex
作者:Gary A. Molander、Christopher P. Corrette
DOI:10.1016/s0040-4039(98)00981-2
日期:1998.7
A catalytic method for the sequential cyclization-silylation of dienes containing one or two 1,1-disubstituted alkene moieties to form various cyclic and bicyclic organosilanes in good yield is presented.
A tandem 1,3-dipolar cycloaddition/electrophilic cyclization sequence: γ,δ-Unsaturated isoxazolines as precursors to ring-fused ethers
作者:Mark J. Kurth、Michael J. Rodriguez
DOI:10.1016/s0040-4020(01)89162-6
日期:——
A tandem1,3-dipolarcycloaddition/electrophiliccyclizationsequence affords cis-fused octahydrobenzo-and hexahydro-2H-cyclopenta[b]furans via the intermediacy of γ,δ-unsaturated isoxazolines.
Use of Cyclopropanols as Conformational Constraints in RCM
作者:Ivan L. Lysenko、Hyung Goo Lee、Jin Kun Cha
DOI:10.1021/ol0605631
日期:2006.6.1
[reaction: see text] Sequential application of the Kulinkovich cyclopropanation of carboxylic esters and RCM of the resulting cis-dialkenyl-tethered cyclopropanols provides an expedientroute to functionalized medium-sized carbocycles. Subsequent elaboration of the cyclopropanol functionality, such as one-carbon ring expansion, to afford synthetically useful alpha,beta-enones is also worth noting.