96391-87-6Relevant academic research and scientific papers
Enantioselective preparation of C2-symmetrical ferrocenyl ligands for asymmetric catalysis
Schwink, Lothar,Knochel, Paul
, p. 950 - 968 (1998)
Corey - Bakshi - Shibata (CBS) reduction of the 1,1'-diacylmetallocenes 5 and 7 provides the C2-symmetrical diols 4 and 10, which proved to be useful starting materials for stereo-controlled ligand synthesis. Diols 4 and 10 can be easily converted to a wide range of diamines, diphosphines, and dithioacetates by nucleophilic substitution of the hydroxyl function with full retention of configuration. Furthermore, the aminophosphines 30 and 31 become easily accessible. Compounds 30 and 31 have been used as ligands in enantioselective cross-coupling of racemic secondary Grignard reagents with vinyl bromides. A selectivity up to 93% ee could be reached for the first time in the preparation of (S)-(E)-1,3-diphenyl-1-butene (34b), which was transformed into the enantiomerically pure chiral building block 37 with a pseudoasymmetric center in a straightforward, three-step synthesis.
Alkylation of Allylic Derivatives. 7. Stereochemistry of Alkylation of the Isomeric trans-α,γ-Methyl(phenyl)allyl Acetates with Lithium Dialkylcuprates and Alkylcyanocuprates
Goering, Harlan L.,Tseng, Chung Chyi
, p. 3986 - 3990 (2007/10/02)
Alkylation of the isomeric trans-α,γ-methyl(phenyl)allyl acetates (2-OAc and 3-OAc) with lithium dialkylcuprates or alkylcyanocuprate is stereospecific.The α-alkylation product is formed with excess inversion, and the γ-alkylation product results from excess anti bonding.Stereospecificity ranges from about 85 to 95 percent in this sterically unbiased system.
