Palladium-Catalyzed Conjugate Addition of Organosiloxanes to α,β-Unsaturated Carbonyl Compounds and Nitroalkenes
作者:Scott E. Denmark、Nobuyoshi Amishiro
DOI:10.1021/jo034763r
日期:2003.9.1
aryltrialkoxysilanes to alpha,beta-unsaturated carbonylcompounds (ketones, aldehydes) and nitroalkenes in the presence of SbCl(3), TBAF, AcOH, and a catalytic amount of Pd(OAc)(2), in CH(3)CN at 60 degrees C, provides the corresponding conjugate addition products in moderate to good yields. The addition of equimolar amounts of SbCl(3) and TBAF is necessary for this reaction to proceed smoothly. The arylpalladium
Conjugate Addition of Mixed Diorganozinc Compounds and Functionalized Organozinc Cuprates to Nitroolefins
作者:Audrius Rimkus、Norbert Sewald
DOI:10.1021/ol026557w
日期:2002.9.1
conjugate addition of symmetrical and mixed diorganozinc compounds as well as functionalized diorganozinc cuprates to nitroolefins leads to synthetically versatile nitro compounds in moderate to good yields. Mixed TMSM-organozinc compounds are suitable reagents for conjugate addition, since the TMSM group is not being transferred. Ipso substitution is observed in the absence of a catalytic amount of
Conjugate Addition of Organozinc Compounds to Nitroolefins
作者:Norbert Sewald、Audrius Rimkus
DOI:10.1055/s-2003-44355
日期:——
excellent yield and enantioselectivity. The products can easily be transformed into beta(2)-homoamino acids, compounds of high relevance for different areas of preparative organic chemistry. 1 Introduction 2 Synthesis of Nitroolefins 3 ConjugateAddition of Organozinc Compounds 3.1 ConjugateAddition of Functionalized Organozinc Cuprates and Diorganozine Compounds 3.2 ConjugateAddition of Alkyl Trimethylsilylmethylzinc
Palladium(II)-Catalyzed Michael-Type Hydroarylation of Nitroalkenes Using Aryltins and Sodium Tetraarylborates
作者:Toshiyuki Ohe、Sakae Uemura
DOI:10.1246/bcsj.76.1423
日期:2003.7
variety of aryltin compounds and sodium tetraarylborates can be employed for Michael-type hydroarylation reactions of nitroalkenes to afford β-arylnitroalkanes in moderate to good yields in the presence of either LiCl, MgCl2, or CaCl2 and a catalytic amount of palladium(II) salt (0.05 molar amount) in acetic acid. Results show that 50–70% of aryl groups out of all in these arylcompounds can be transferred
Preparation of polyfunctional nitro olefins and nitroalkanes using the copper-zinc reagents RCu(CN)ZnI
作者:Carole Jubert、Paul Knochel
DOI:10.1021/jo00046a027
日期:1992.9
The addition of the copper-zinc reagents RCu(CN)ZnX to a variety of nitro olefins produces polyfunctional nitroalkanes in high yields. The intermediate zinc or copper nitronates can be directly submitted to a Nef reaction (O3,-78-degrees-C) and converted to polyfunctional ketones in a one-pot procedure. The addition of RCu(CN)ZnX to nitro olefins bearing a leaving group (RSO2, RS) in the beta-position provides pure (E)-nitro olefins in excellent yields. The reaction has been applied for the stereoselective preparation of 1,3-nitrodienes and for a Diels-Alder reaction precursor.