1246896-00-3Relevant academic research and scientific papers
Br?nsted Acid Enabled Nickel-Catalyzed Hydroalkenylation of Aldehydes with Styrene and its Derivatives
Han, Xing-Wang,Zhang, Tao,Zheng, Yan-Long,Yao, Wei-Wei,Li, Jiang-Fei,Pu, You-Ge,Ye, Mengchun,Zhou, Qi-Lin
supporting information, p. 5068 - 5071 (2018/03/27)
A Br?nsted acid enabled nickel-catalyzed hydroalkenylation of aldehydes and styrene derivatives has been developed. The Br?nsted acid acts as a proton shuttle to transfer a proton from the alkene to the aldehyde, thereby leading to an economical and byproduct-free coupling. A series of synthetically useful allylic alcohols were obtained through one-step reactions from readily available styrene derivatives and aliphatic aldehydes in up to 88 % yield and with high linear selectivity.
Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines
Yan, Liang,Xu, Jing-Kun,Huang, Chao-Fan,He, Zeng-Yang,Xu, Ya-Nan,Tian, Shi-Kai
supporting information, p. 13041 - 13045 (2016/09/09)
A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2, 4 mol % (S)-SegPhos, and 10 mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.
Accessing Both Retention and Inversion Pathways in Stereospecific, Nickel-Catalyzed Miyaura Borylations of Allylic Pivalates
Zhou, Qi,Srinivas, Harathi D.,Zhang, Songnan,Watson, Mary P.
supporting information, p. 11989 - 11995 (2016/10/07)
We have developed a stereospecific, nickel-catalyzed Miyaura borylation of allylic pivalates, which delivers highly enantioenriched α-stereogenic γ-aryl allylboronates with good yields and regioselectivities. Our complementary sets of conditions enable access to either enantiomer of allylboronate product from a single enantiomer of readily prepared allylic pivalate substrate. Excellent functional group tolerance, yields, regioselectivities, and stereochemical fidelities are observed. The stereochemical switch from stereoretention to stereoinversion largely depends upon solvent and can be explained by competitive pathways for the oxidative addition step. Our mechanistic investigations support a stereoretentive pathway stemming from a directed oxidative addition and a stereoinvertive pathway that is dominant when MeCN blocks coordination of the directing group by binding the nickel catalyst.
Pd-Catalyzed stereospecific allyl-aryl coupling of allylic alcohols with arylboronic acids
Ye, Jiang,Zhao, Jingming,Xu, Jing,Mao, Yuxue,Zhang, Yong Jian
supporting information, p. 9761 - 9763 (2013/10/21)
An efficient method for Pd-catalyzed stereospecific allyl-aryl coupling of allylic alcohols with arylboronic acids has been described. The reactions proceeded smoothly in the presence of Pd2(dba)3· CHCl3 and racemic BINAP
Catalytic highly enantioselective alkylation of aldehydes with deactivated grignard reagents and synthesis of bioactive intermediate secondary arylpropanols
Liu, Yi,Da, Chao-Shan,Yu, Sheng-Li,Yin, Xiao-Gang,Wang, Jun-Rui,Fan, Xin-Yuan,Li, Wei-Ping,Wang, Rui
supporting information; experimental part, p. 6869 - 6878 (2010/11/24)
Because of the high reactivity of Grignard reagents, a direct, highly enantioselective Grignard reaction with aldehydes has rarely been disclosed. In this report, Grignard reagents were introduced with bis[2-(N,N′- dimethylamino)ethyl] ether (BDMAEE) to effectively deactivate their reactivity; thus, a highly enantioselective alkylation of aldehydes with Grignard reagents resulted from catalysis by (S)-BINOL-Ti(OiPr)2. It is thought that BDMAEE chelates the in situ generated salts MgBr2 from a Schlenk equilibrium of RMgBr and Mg(OiPr)Br from transmetalation of RMgBr with Ti(OiPr)4. The Mg salts can actively promote the undesired background reaction to give the racemate. The chelation definitely inhibits the catalytic activity of the Mg salts, suppresses the unwanted background reaction, and enables the highly enantioselective addition catalyzed by (S)-BINOL-Ti(OiPr)2. Consequently, the Mg salt byproducts were not removed, less Ti(OiPr)4 than RMgBr was used, and extremely low temperature was avoided in this catalytic asymmetric reaction in comparison with the research disclosed before. Various alkyl Grignard reagents were investigated in the asymmetric addition, and iBuMgBr resulted in the highest enantioselectivity, >99%. Furthermore, important intermediate secondary arylpropanols for chiral drug synthesis were effectively synthesized with high enantioselectivity, up to 97%, in one step.
