for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
Synthèse régiospécifique d'amines tertiaires à groupe secondaire bi-insaturé
作者:D. Mesnard、L. Miginiac
DOI:10.1016/0022-328x(89)85018-1
日期:1989.9
We describe the regiospecific preparation of tertiary amines with a symmetrical (or dissymmetrical) doubly unsaturated secondary group, by reaction of an allylic, vinylic or acetylenic organometallic derivative with a dialkylformamido acetal, a chlorinated iminium salt or an alkynyl aminoether.
Nickel-Catalyzed Chemo- and Enantioselective Coupling between Cyclobutanones and Allenes: Rapid Synthesis of [3.2.2] Bicycles
作者:Xuan Zhou、Guangbin Dong
DOI:10.1002/anie.201609489
日期:2016.11.21
Herein an intramolecular nickel‐catalyzed (4+2) coupling between cyclobutanones and allenes, by C−C cleavage, is reported. The reaction provides a distinct approach for accessing [3.2.2] bicyclic scaffolds which are challenging to prepare through conventional approaches. The reaction is efficient, chemoselective, and pH/redox neutral. Room temperature conditions and low catalyst loadings can be adopted
Studies on Hydrozirconation of 1-Alkynyl Sulfoxides or Sulfones and the Application for the Synthesis of Stereodefined Vinyl Sulfoxides or Sulfones
作者:Xian Huang、Dehui Duan、Weixin Zheng
DOI:10.1021/jo0111154
日期:2003.3.1
Z-beta-sulfonyl alpha,beta-unsaturated ketones, and Z-beta-alkynyl vinyl sulfones. Although the reaction mechanisms are still not clear, the neighboringgroupparticipation of the sulfinyl or sulfonyl group may be playing an important role in this unique hydrozirconation reaction.
A Facile Stereoselective Synthesis of (<i>Z</i>)-2-ethoxycarbonyl-substituted 1,3-enynes from (<i>E</i>)-α-stannyl-α,β-unsaturated esters and alkynyl bromides
作者:Ruchun Dai、Zhiwen Xi、Mingzhong Cai
DOI:10.3184/030823409x401772
日期:2009.3
Palladium-catalysed hydrostannylation of alkynyl esters in benzene at room temperature gives regio- and stereoselectively (E)-α-stannyl-α,β-unsaturated esters in good yields. (E)-α-Stannyl-α,β-unsaturated ethyl esters are difunctional group reagents which undergo Stille coupling reactions with alkynyl bromides in the presence of Pd(PPh3)4 and Cul co-catalyst to afford stereoselectively (Z)-2-ethoxycarbonyl-substituted