128217-20-9Relevant academic research and scientific papers
Asymmetric 1,4-addition of alkenylzirconium reagents to α,β-unsaturated ketones catalyzed by chiral rhodium complexes
Oi, Shuichi,Sato, Takashi,Inoue, Yoshio
, p. 5051 - 5055 (2004)
Highly enantioselective 1,4-addition of alkenylzirconocene chlorides to α,β-enones was found to be catalyzed by a chiral rhodium complex generated from [Rh(cod)(MeCN)2]BF4 and (S)-BINAP. The reaction can be applied to either cyclic or acyclic enones and the optical yield was up to 99% ee. The reaction mechanism would involve the transmetalation between the alkenylzirconocene chloride and the rhodium complex to give the alkenylrhodium species as a key intermediate.
Nickel acetylacetonate-induced 1,4-additions of 1-alkenyl(disiamyl)boranes to α,β-unsaturated ketones, esters and nitriles
Yanagi, Teiji,Sasaki, Hirotomo,Suzuki, Akira,Miyaura, Norio
, p. 2503 - 2509 (1996)
The conjugate addition of 1-alkenyl(disiamyl)boranes to α,β-unsaturated ketones, esters, or nitriles was carried out in the presence of Ni(acac)2 and triethylamine in DMF. The reactions provided γ,δ-unsaturated ketones, esters, and nitriles in
Enantioselective 1,4-additions of ClMeAl(CHCHR) (R = alkyl, alkenyl, Ph) to cyclohexenones
Willcox,Woodward,Alexakis
, p. 1655 - 1657 (2014/02/14)
Chloromethylvinyl alanes (E)-ClMeAl(CH=CHR) prepared directly from terminal alkynes undergo 1,4-addition to cyclohexenone and 3-methylcyclohexenone in moderate to good yield (30-70%) and good to excellent stereoselectivity (80-98% ee) using readily availa
Preparation of polyfunctional diorganomercurials and their transmetallation to diorganozincs. Applications to the preparation of optically active secondary alcohols
Rozema, Michael J.,Rajagopal, Duddu,Tucker, Charles E.,Knochel, Paul
, p. 11 - 27 (2007/10/02)
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).
