94051-93-1Relevant articles and documents
Enantioconvergent Arylation of Racemic Secondary Alcohols to Chiral Tertiary Alcohols Enabled by Nickel/N-Heterocyclic Carbene Catalysis
Cai, Yuan,Shi, Shi-Liang
supporting information, p. 11963 - 11968 (2021/08/20)
The direct upgrading reaction of simple and readily available achiral alcohols via C-H functionalization is an ideal strategy to prepare value-added chiral higher alcohols. Herein, we disclose the first enantioconvergent upgrading reaction of simple racemic secondary alcohols to enantioenriched tertiary alcohols. An N-heterocyclic carbene (NHC)-nickel catalyst was leveraged to enable this highly efficient formal asymmetric alcohol α-C-H arylation via a dehydrogenation using phenyl triflate as a mild oxidant followed by asymmetric addition of arylboronic esters to the transient ketones. Mechanistic studies and control experiments were conducted to reveal the possible reasons for the exceptional control over chemo- and enantioselectivity.
Catalytic Enantioselective Arylation and Heteroarylation of Ketones with Organotitanium Reagents Generated In Situ
Matsuda, Atsushi,Ushimaru, Tomoya,Kobayashi, Yusuke,Harada, Toshiro
supporting information, p. 8605 - 8609 (2017/06/30)
A practical and useful, catalytic enantioselective method has been developed for the synthesis of tertiary diaryl and aryl heteroaryl carbinols starting from commercially available aromatic ketones and aryl or heteroaryl bromides. In this method, organotitanium reagents are generated in situ from the bromides by lithiation with nBuLi followed by transmetallation of the resulting organolithiums with ClTi(OiPr)3. Treatment of the ketones with the titanium reagents in the presence of (R)-3-(3,5-bistrifluoromehthylphenyl)-1,1′-bi-2-naphthol (BTFP-BINOL) affords the corresponding tertiary alcohols in high enantioselectivities and yields. The reaction can also start with furan and 2-thienyllithium. The method is operationally simple and can be conducted on a 10-mmol scale without any difficulties.
Zn(salen)-catalyzed enantioselective phenyl transfer to aldehydes and ketones with organozinc reagent
Shimizu, Keisuke,Uetsu, Hidenori,Gotanda, Takashi,Ito, Katsuji
, p. 1238 - 1242 (2015/03/31)
Abstract A chiral zinc complex of salen was found to be an efficient catalyst for the phenyl transfer of organozinc reagent to aromatic aldehydes and ketones. High enantioselectivities were obtained in reactions of both aromatic aldehydes and ketones (up to 97% and 92% ee, respectively).