- Preparation of polyfunctional diorganomercurials and their transmetallation to diorganozincs. Applications to the preparation of optically active secondary alcohols
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Two new methods of preparation of functionalized diorganomercurials have been developed.The first method involves a substitution reaction of (ICH2)2Hg with zinc-copper reagents FG-RCu(CN)ZnI in THF/DMF at -60 deg C.Functional groups such as an ester, nitrile, ketone, phosphonate, halide, and boronic ester are tolerated in this reaction.The second method involves a reductive transmetallation between polyfunctional organozinc halides and mercurous chloride (Hg2Cl2).This very convenient procedure provides a rapid route to various functionalized diorganomercurials in good yields (61-89percent yield).The synthetic utility of these mercury organometallics is demonstrated.Their transmetallation with zinc dust (toluene, 80 deg C, 3-5 h) affords dialkylzincs which add enantioselectively to aldehydes in the presence of a catalytic amount (20 molpercent) of the norephedrine derivative 13.This transmetallation can also be used to prepare stereoselectively (E)-alkenylzinc halides (> 98percent E).Addition of Cl(H)ZrCp2 to (E)-5-chloropentenylzinc bromide in CH2Cl2 (25 deg C, 1 min) affords a 1,1-bimetallic of zinc and zirconium Cl(CH2)4CH(ZnBr)ZrCp2(Cl) which reacts stereoselectively with an aldehyde providing the (E)-disubstituted olefin (49percent yield; 100percent E).
- Rozema, Michael J.,Rajagopal, Duddu,Tucker, Charles E.,Knochel, Paul
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- NUCLEOPHILIC SUBSTITUTION IN ORGANOMERCURY HALIDES BY A FREE RADICAL CHAIN PROCESS
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Primary and secondary alkylmercury halides react with the salts of secondary nitroalkanes to afford tertiary nitroalkanes, mercury metal, and halide ion.The reaction is light initiated and is strongly inhibited by radical scavengers.Cyclized products resu
- Russel, Glen A.,Hershberger, James,Owens, Karen
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