69747-29-1Relevant articles and documents
Grignard allylic substitution reaction catalyzed by 1,2,3-triazol-5-ylidene magnesium complexes
Nomura, Ryosuke,Tsuchiya, Yuji,Ishikawa, Hiroyuki,Okamoto, Sentaro
, p. 1360 - 1363 (2013/05/08)
Allylic chlorides and phosphates reacted with alkyl-Grignard reagent in an SN2′-selective manner in the presence of a catalytic amount of 1,2,3-triazol-5-ylidenes to provide α-branched alkenes. Copyright
ortho-Chelating Arenethiolatocopper(I) Complexes as Versatile Catalysts in the Regioselective Cross-Coupling of Allylic Derivatives with nBuMgI - An Example of Reversed Reactivity of Leaving Groups
Persson, Eva S. M.,Klaveren, Mayra van,Grove, David M.,Baeckvall, Jan E.,Koten, Gerard van
, p. 351 - 359 (2007/10/03)
The regioselectivity in the arenethiolactocopper(I)-catalyzed cross-coupling reaction of allylic substrates was studied.It was found that allylic acetates gave highly γ-selective reactions in Et2O at 0 deg C with slow addition of the Grignard reagent, whereas α-selective reactions were obtained in THF at -30 deg C with fast addition of the Grignard reagent.It is proposed that the formation of an intermediate in Et2O, in which the allylic acetate coordinates in a bidentate fashion to the arenethiolatocopper(I) catalyst, dramatically increases the reactivity of the leaving group and results in excellent γ-selectivity.The remarkable observation that an allylic acetate can be made more reactive than an allylic chloride by using the arenethiolatocopper(I) catalyst 1a supports the theory of a bidentate coordination of the substrate to the catalyst through its double bond and acetate oxygen. - Keywords: allylic substrates . carbon-carbon coupling . catalysis . copper compounds
Copper-catalyzed reactions of organotitanium reagents. Highly selective SN2′-allylation and conjugate addition
Arai, Masayuki,Lipshutz, Bruce H.,Nakamura, Eiichi
, p. 5709 - 5718 (2007/10/02)
In the presence of a catalytic amount of CuI·ILiCl, alkyltitanium (RTi(O-I-Pr)3) and titanate reagents (RnTi(O-i-Pr)5-nLi) undergo highly selective SN2′-alkylation reactions with allylic chlorides and allylic diethylphosphates in high yields. The regioselectivity of the reaction is as high as 99.8%. The reaction proceeds with excellent anti-stereoselectivity with respect to the nucleophile and the leaving group, and exhibits high 1,2-anti-diastereoselectivity with a δ-chiral allylic chloride. The catalytic copper reagent is also a mild agent to transfer an alkyl group to an enone in the presence of Me3SiCl. The alkyltitanium-based catalytic reagent selectively reacts with an allylic phosphate rather than with an enone, while in the presence of a silicon activator, it reacts preferentially with the enone rather than with the phosphate. 1H NMR studies on a mixture of Me2CuLi and TiCl(O-i-Pr)3 provided information on reagent composition.
