19781-77-2Relevant articles and documents
Ring closing metathesis and metal-catalyzed cyclopropanation for the preparation of sultone derivatives
Ali, Korany A.,Metz, Peter
, p. 19 - 29 (2019/04/17)
Ring closing metathesis (RCM) using Grubbs catalyst 2nd generation as a catalyst was applied to prepare series of novel unsaturated sultones with high yields. Many attempts, were applied for the cyclopropanation of the allylic sultones by Simmon-smith cyclopropanation using diethyl zinc/diiodomethane or Zn-Cu/diiodomethane but in each case the corresponding cyclic adduct was not formed. A novel palladium or preferably rhodium-catalyzed cyclopropanation of unsaturated sultones with ethyl diazoacetate was achieved by the transition metal-catalyzed transfer of a CH-CO2Et unit. The reaction was applied by a portion-wise addition of ethyl diazoacetate over 6h to a mixture of the sultones and palladium(II) acetate or rhodium(II) acetate dimer under low temperature (0-20 o C). The desired products of the cyclopropanation were achieved in each case, as a single diastereomer with 33- 37% yield in the allylic sultones and 10% for vinylic sultone.
Catalyzed Enantioselective Alkylation of Aldehydes
Bolm, Carsten,Schlingloff, Gunther,Harms, Klaus
, p. 1191 - 1204 (2007/10/02)
Enantioselective alkylation of a variety of aldehydes with diethylzinc was achieved by using catalytic amounts of optically active pyridines and C2-symmetric 2,2'-bipyridines.The products were obtained in good yields with high enantioselectivit
AMINYL RADICAL CYCLIZATION BY MEANS OF ANODIC OXIDATION. STEREOSELECTIVE SYNTHESIS OF cis-1-METHYL-2,5-DISUBSTITUED PYRROLIDINES
Tokuda, Masao,Yamada, Yasufumi,Takagi, Toshiya,Suginome, Hiroshi,Furusaki, Akio
, p. 6085 - 6088 (2007/10/02)
Neutral aminyl radicals generated by anodic oxidation of lithium alkenylamides 2 undergo a stereoselective cyclization to give cis-1-methyl-2,5-disubstituted pyrrolidines 4.Their cis stereochemistry was confirmed by a comparison with trans-1,2-dimethyl-5-phenylpyrrolidine, the structure of which was established by X-ray crystallographic analysis of its quarternary ammonium bromide 6.
