Synthesis of oxygenated heterocycles from cyclic allylsiloxanes using ring-closing olefin metathesis
作者:Christophe Meyer、Janine Cossy
DOI:10.1016/s0040-4039(97)10147-2
日期:1997.11
Cyclic allylsiloxanes were prepared from allyldimethylsilyl ethers of various alkenols by using a catalytic ring-closingmetathesis (RCM) reaction. The transformation of these cyclic allylsiloxanes into stereoselectively substituted tetrahydrofurans and tetrahydropyrans was achieved by using a silyl modified Sakurai reaction.
Stereoselective Synthesis of 2,3,5-Trisubstituted Tetrahydrofurans by an Allyl Silane Metathesis - Nucleophilic Addition Sequence
作者:John Cassidy、Stephen Marsden、Geoffrey Stemp
DOI:10.1055/s-1997-1062
日期:——
Functionalised cyclic allyl silanes have been prepared by the ring closing metathesis of allyldimethylsilyl ethers of homoallylic alcohols. Treatment of these allyl silanes with aldehydes in the presence of boron trifluoride etherate gives high yields of 2,3,5-substituted tetrahydrofurans. Stereoselectivities are excellent for aldehydes with primary substituents, good for secondary substituents and modest for tertiary substituents.
Indenylidene Complexes of Ruthenium: Optimized Synthesis, Structure Elucidation, and Performance as Catalysts for Olefin Metathesis—Application to the Synthesis of the ADE-Ring System of Nakadomarin A
complex 3 is as good as or even superior to the classical Grubbs carbene 1 in terms of yield, reaction rate, and tolerance towards polar functional groups. Complex 3 turns out to be the catalyst of choice for the synthesis of the enantiopure core segment 77 of the marine alkaloid nakadomarin A 60 comprising the ADE rings of this target. Together with a series of other examples, this particular application
Coordinatively unsaturated ruthenium allenylidene complexes: highly effective, well defined catalysts for the ring-closure metathesis of α,ω-dienes and dienynes
作者:Alois Fürstner、Monika Liebl、Anthony F. Hill、James D. E. T. Wilton-Ely
DOI:10.1039/a900187e
日期:——
The well defined, conveniently accessible and coordinatively unsaturated allenylidene complexes [RuCl2(CC CPh2)(PCy3)2] and [Ru2Cl4(CCCPh2)(PCy3)(η-MeC6-H4Pri-4)] are highly effective catalysts for the ambient temperature ring-closure metathesis of α,Ï-dienes and dienynes, illustrated by the facile and high yielding formation of variously functionalised 5, 6, 7, 8, 15, 16 and 18 membered mono- and bi-cyclic ring systems.