Reactions of stoichiometric higher order, mixed lithio magnesio organocuprates
作者:Bruce H. Lipshutz、David A. Parker、Sam L. Nguyen、Keith E. McCarthy、John C. Barton、Scott E. Whitney、Hiyoshizo Kotsuki
DOI:10.1016/s0040-4020(01)90576-9
日期:1986.1
2-lithiothiophene and RMgX. Reactions of various members of this new class of reagents are described, including substitution and conjugateaddition processes, where the ligand derived from the Grignard reagent is selectively transferred. The effects of added BF3.Et2O are discussed. Some comparison reactions with the corresponding lower order reagents, RCu(CN)MgBr, have also been carried out. Evidence is presented
More highly mixed, higher order cyanocuprates “RT(2-thienyl)Cu(CN)Li2”. Efficient reagents which promote selective ligand transfer
作者:Bruce H. Lipshutz、Joseph A. Kozlowski、David A. Parker、Sam L. Nguyen、Keith E. McCarthy
DOI:10.1016/0022-328x(85)87388-5
日期:1985.4
forms a new reagent, “RT(2-thienyl)Cu(CN)Li2.” This species selectively transfers the RT ligand in substitution reactions with epoxides and halides. In conjugateaddition processes, the cuprate reacts with unhindered substrates, while β,β-disubstituted cases unexpectedly afford products resulting from 1,2-addition of the thiophene group. The prospects for use of these reagents in the synthesis of polyene
有机锂(R T Li)和2-lithiothiophene(2-噻吩基)与CuCN的结合形成了一种新试剂“ R T(2-噻吩基)Cu(CN)Li 2”。该物种在与环氧化物和卤化物的取代反应中选择性转移R T配体。在共轭加成过程中,铜酸盐与不受阻碍的底物反应,而β,β-二取代的情况出乎意料地提供了由噻吩基的1,2-加成产生的产物。讨论了这些试剂在多烯大环内酯类抗生素合成中的应用前景。
A model study for the total synthesis of (±)-scopadulin: stereoselective construction of the A/B ring system with desired functionalities
A model study toward the total synthesis of (±)-scopadulin is described. Stereocontrolledsynthesis of the A/B ring system with desired functionalities was achieved by stereoselective cyanation of a bicyclic enone with Et2AlCN, diastereoselective construction of a quaternary carbon at C-4 with LDA-BOMCl, and conversion of the cyano group into a methyl group.
Chemistry of higher order, mixed organocuprates. reactions of α,β-unsaturated ketones.
作者:Bruce H. Lipshutz、Robert S. Wilhelm、Joseph Kozlowski
DOI:10.1016/s0040-4039(00)87698-4
日期:1982.1
Organocuprates of general formula R2Cu(CN)Li2 react rapidly with α,β-unsaturated ketones at low temperatures and in high yields to deliver ligands in a conjugate manner. These reagents apparently do not require the use of additives for stabilizing or solubilizing purposes.