40395-23-1Relevant academic research and scientific papers
SN2'-Regio- and Diastereoselective Allylation of Organozine Raegents
Arai, Masayuki,Kawasuji, Takashi,Nakamura, Eiichi
, p. 357 - 360 (1993)
Dialkylzinc reagents, R2Zn and R2Zn*LiCl, undergo an SN2'-regio- and diastereoselective allylation reaction with substituted allylic chlorides and phosphates in the presence of a coordinating additive.
Reactivity of mixed organozinc and mixed organocopper reagents: 14. Phosphine-nickel catalyzed aryl-allyl coupling of (n-butyl)(aryl)zincs. Ligand and substrate control on the group selectivity and regioselectivity
Kalkan, Melike,Erdik, Ender
, p. 28 - 36 (2016/06/09)
The group selectivity and regioselectivity in the allylation of mixed (n-butyl)(aryl)zinc reagents in THF depends on the nickel catalyst type and also on nature of the allylic substrate. Allylation of (n-butyl)(phenyl)zinc reagent with alkyl substituted primary allylic chlorides and acetates in the presence of NiCl2(dppf) catalysis affords the phenyl coupling product with γ-selectivity. However, allylation with aryl substituted primary allylic substrates results in both phenyl- and alkyl-coupling products with medium α-selectivity in the presence of NiCl2(dppf) catalysis whereas phenyl coupling product is formed with α-selectivity in the presence of NiCl2(Ph3P)2 catalysis. This new NiCl2(dppf) catalyzed protocol for γ-selective aryl allylation of (n-butyl)(aryl)zinc reagents with alkyl substituted primary allylic chlorides in THF at room temperature provides an atom economic alternative to allylation of (aryl)2Zn reagents. A mechanism for the dependence of group selectivity and regioselectivity of Ni catalyzed allylation of (n-butyl)(aryl)zinc reagents on the catalyst ligand and the substrate was proposed.
Catalyst-controlled reverse selectivity in C-C bond formation: NHC-Cu-catalyzed α-selective allylic alkylation with organolithium reagents
Pizzolato, Stefano F.,Giannerini, Massimo,Bos, Pieter H.,Fa?anás-Mastral, Martín,Feringa, Ben L.
, p. 8142 - 8145 (2015/05/20)
An efficient and highly α-selective copper-catalyzed allylic alkylation of allylic halides with organolithium reagents is presented. The use of N-heterocyclic carbenes as ligands is key to reverse the common γ-selectivity of this transformation and gives rise to the corresponding linear products with high levels of regioselectivity.
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
Short synthesis of chiral 4-substituted (S)-imidazolinium salts bearing sulfonates and their use in γ-selective reactions of allylic halides with grignard reagents
Latham, Christopher M.,Blake, Alexander J.,Lewis, William,Lawrence, Matthew,Woodward, Simon
supporting information; experimental part, p. 699 - 707 (2012/03/11)
A one-pot reaction of Boc-protected amino alcohols and 2-sulfobenzoic anhydride followed by the addition of a wide variety of primary amines has allowed rapid access to diverse libraries of amidosulfonates 1,2-C 6H4(SO3su
Grignard allylic substitution catalyzed by imidazol-2-ylidene- and imidazol-4-ylidene-magnesium complexes
Okamoto, Sentaro,Ishikawa, Hiroyuki,Shibata, Yoshimi,Suhara, Yu-Ichiro
supporting information; experimental part, p. 5704 - 5707 (2010/11/16)
In the presence of a catalytic amount of 1,2-disubstituted or 1,2,3-trisubstituted imidazolium salts, γ-substituted allyl chlorides reacted with alkyl Grignard reagents to undergo substitution reactions in an SN2′-selective fashion, where the magnesium ate complexes [(N-heterocyclic carbene-MgR3)-(MgX)+] of imidazol-2-ylidenes or imidazol-4-ylidenes, generated in situ, were postulated as the active species. It was observed that the reactions with imidazol-4-ylidene catalysts were faster than those with imidazol-2-ylidenes. Enantioselective catalysis using a chiral imidazolium salt was preliminarily investigated.
Cobalt-catalyzed regioselective dehydrohalogenation of alkyl halides with dimethylphenylsilylmethylmagnesium chloride
Kobayashi, Tsuneyuki,Ohmiya, Hirohisa,Yorimitsu, Hideki,Oshima, Koichiro
supporting information; scheme or table, p. 11276 - 11277 (2009/02/05)
Cobalt-catalyzed reactions of haloalkanes with dimethylphenylsilylmethylmagnesium chloride result in highly regioselective dehydrohalogenation. The reaction does not follow the conventional E2 elimination mechanism but includes β-hydride elimination from the corresponding alkylcobalt intermediate. The interesting reaction mechanism of the cobalt-catalyzed dehydrohalogenation offered unique transformations that are otherwise difficult to attain. Copyright
Copper catalyzed magnesium-Barbier reaction for γ-selective alkyl-allyl coupling
Erdik, Ender,Ko?o?lu, Melike
, p. 4211 - 4214 (2008/02/08)
CuCN catalyzed alkyl-allyl coupling under magnesium-Barbier conditions occurs regioselectively and affords predominantly the γ-products in good to high yields. This one-pot CuCN catalyzed reaction utilising Mg, an alkyl halide and an allylic substrate in THF at room temperature provides an easy alternative to the classical CuCN catalyzed γ-allylation of alkyl Grignard reagents.
Screening of ligands in the asymmetric metallocenethiolatocopper(I)-catalyzed allylic substitution with Grignard reagents
Cotton, Hanna K.,Norinder, Jakob,B?ckvall, Jan-E.
, p. 5632 - 5640 (2007/10/03)
Screening of metallocenethiolate ligands for copper(I)-catalyzed substitution of allylic acetates with Grignard reagents has been carried out. The previously used ligand, lithium (R,Sp)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4a), possessing both central and planar chirality, was the starting point for the screening. It was found that the diastereomeric ligand lithium (R,Rp)-2-(1-dimethylaminoethyl)ferrocenylthiolate (4b) exhibiting reversed planar chirality gave increased enantioselectivity in the allylic substitution, at least when cinnamyl acetate was used as a substrate. The ruthenocene-based ligand lithium (R,Sp)-2-(1-dimethylaminoethyl)ruthenocenylthiolate (4c) gave an enhanced reaction rate, but lower chiral induction. The use of disulfide bis[(R,Sp)-2-(1-dimethylaminoethyl)ferrocenyl]disulfide (7a) as a ligand precursor worked well but resulted in lower enantioselectivity.
Novel nickel-catalyzed coupling reaction of allyl ethers with chlorosilanes, alkyl tosylates, or alkyl halides promoted by vinyl-Grignard reagent leading to allylsilanes or alkenes
Terao, Jun,Watabe, Hiroyasu,Watanabe, Hiroyuki,Kambe, Nobuaki
, p. 1674 - 1678 (2007/10/03)
A new method for a carbon-silicon or carbon-carbon bond forming reaction between allyl ethers and chlorosilanes, alkyl tosylates, or alkyl halides giving rise to allylsilanes or alkenes has been developed. This reaction proceeds efficiently at ambient temperature by the combined use of nickel catalysts and a vinyl-Grignard reagent. A possible reaction pathway involving the formation of allyl-Grignard reagents via transmetallation of π-allylnickel complexes with the vinyl-Grignard reagent and subsequent trapping of the thus formed allyl-Grignard reagents with electrophiles is proposed.
