and P(NMe2)3 as a new ligand for rhodium(I)-catalyzed asymmetric1,4-addition of arylboronicacids to α,β-unsaturated carbonyl compounds. The effects of 5a and Feringa’s monodentate phosphoramidite (4, R1, R2 = Et) on the yields and enantioselectivities were fully investigated. The reaction was significantly accelerated in the presence of a base such as KOH and Et3N, allowing the reaction to be completed
Cationic rhodium(I) complex prepared from Shibasaki’s linked-BINOL and [Rh(nbd)2]BF4 catalyzed asymmetric 1,4-addition of arylboronic acids to enones at room temperature with high enantioselectivities up to 99.8%ee.
1,4-Addition of arylboronic acids to β-aryl-α,β-unsaturated ketones and esters catalyzed by a rhodium(I)–chiraphos complex for catalytic and enantioselective synthesis of selective endothelin A receptor antagonists
An enantioselective synthesis of acyclic β-diaryl ketones and esters via 1,4-addition of arylboronic acids to β-aryl-α,β-unsaturatedketones or esters is described. The complex in situ prepared from [Rh(nbd)2]BF4 and chiraphos was found to be an excellent catalyst to achieve high enantioselectivities in a range of 83–89% ee for the ketone derivatives and 78–94% ee for tert-butyl β-arylacrylate derivatives
Asymmetric 1,4-addition of [ArBF3]K to cyclic and acyclic enones was carried out in aqueous methanol in the presence of a chiral phosphine-dicationic palladium(II) catalyst. A palladium complex of (S,S)-dipamp gave optically active β-arylketones of up to 96 % ee for 2-cyclohexenone and 2-cycloheptenone. A palladium-(S,S)-chiraphos complex resulted in 82–97 % ee for 2-cyclopentenone and acyclic enones.
METHOD FOR PRODUCING -DIARYL ELECTRON-WITHDRAWING GROUP SUBSTITUTED COMPOUND
申请人:Japan Science and Technology Agency
公开号:EP2042478A1
公开(公告)日:2009-04-01
An electron withdrawing group substituted β-arylolefin derivative represented by general formula (I)
(in the formula, Ar1 represents an aryl group, E represents a formyl, acyl and so on) is allowed to react with an arylboronic acid represented by general formula (II) Ar2-BXmMn in the general formula (IV) RhYoL1p (Chiraphos)q (in the formula, Y represents ClO4, BF4, PF6, SbF6, OTf, halogen atom, hydroxyl group, alkoxy group or acyloxy group, L1 represents an organic ligand) to produce an optically active β-diaryl electron withdrawing group substituted compound represented by general formula (V)