Insertion of metallated epoxides into zirconacycles

Applications of stoichiometric transition metal complexes in organic synthesis

“…9 Related to this, the reaction of metallated epoxides produces highly functionalised products from the convergence of four different reacting partners (Scheme 5). 10 Other papers have shown that carbenoid insertion into alkenylzirconocenes provides a convergent synthesis of functionalised allylmetallates, 11 and produced a short total synthesis of galbulin and isogalbulin. 12 The reaction of zirconocene complexes with enol ethers has been used as a way to access vinylzirconium derivatives in a stereocontrolled manner.…”

Reactivity of Oxiranes with Organolithium Reagents

“…Intermolecular C−Li insertion followed by Li 2 O elimination occurs by raising the temperature 271 , and (E) vinylsilanes are obtained stereoselectively (Scheme 80). Reaction of lithiooxiranes with aluminum 285 , zirconium 290 and silicon 291 -293 reagents leads to the corresponding ate complexes, which undergo 1,2-metallate rearrangements.…”

“…Lithiooxiranes stabilized by a carbethoxy 311 or a cyano 290,311,318 group can be readily prepared by deprotonation by LDA at −80 • C and quenched with various electrophiles. The lithiooxirane 193 (Scheme 85) is configurationally stable at this temperature, whereas α-cyano lithiooxiranes show 318 a limited configurational stability.…”

Recent Developments in the Chemistry of Lithiated Epoxides

“…Whitby and Kasatkin recently showed that silyl-, phenyl-, and cyano-stabilised a-lithiated epoxides underwent reactions with zirconacycles (as electrophiles) via transmetallation and (formal) insertion into a C-Zr bond. 61 The reaction involving a silyl-stabilised lithiated epoxide 101 and zirconacycles 102 (R 1 , R 2 = H, alkyl) mainly yields the corresponding vinylsilane 103, where one epoxide-derived fragment is introduced (Scheme 38). Desilylated olefins and products of double insertion are also sometimes observed.…”