642491-11-0Relevant academic research and scientific papers
Construction of P-stereogenic center by selective ligation of N-P-N type ligands and application to asymmetric allylic substitution reactions
Yamagishi, Takamichi,Ohnuki, Masatoshi,Kiyooka, Takahiro,Masui, Dai,Sato, Kiyoshi,Yamaguchi, Motowo
, p. 3275 - 3279 (2003)
Chiral bisoxazolylphosphine ligands 1 [(S,S)-PhP(Ox-R)2: R=Me, iPr, tBu] with an N-P-N backbone were prepared from chiral 4-alkyl-2-phenyl-4,5-dihydrooxazole compounds. These ligands coordinated to Pd(II) ion as bidentate ligands selectively to give a stereogenic phosphorus atom. The Pd-(S,S)-PhP(Ox-tBu)2 1c catalyst evoked high enantioselectivity in asymmetric allylic substitutions of acyclic substrates using dimethyl sodiomalonate as nucleophile. In the reaction of 3-penten-2-yl acetate, which affords a π-allyl intermediate with a small steric factor, the Pd-1c catalyst successfully induced very high enantioselectivity (94% ee) indicating the effectiveness of the P-stereogenic center formed by selective ligation of ligand 1. In the reaction of cyclic substrates, moderate to high enantioselectivity was obtained by Pd-1 catalyst using the sodium salt of dimethyl methylmalonate.
Cobalt-Catalyzed Regio- and Enantioselective Allylic Amination
Ghorai, Samir,Chirke, Sahadev Shrihari,Xu, Wen-Bin,Chen, Jia-Feng,Li, Changkun
supporting information, p. 11430 - 11434 (2019/08/20)
The first earth-abundant cobalt-catalyzed highly branched- and enantioselective allylic amination of racemic branched allylic carbonates bearing alkyl groups with both aromatic and aliphatic amines has been developed. The process allows rapid access of allylic amines in high yields with exclusively branched selectivity and excellent enantioselectivities (normally 99% ee) under mild reaction conditions.
