A novel ruthenium catalyst on the basis of a chiral monophosphorus ligand is efficient for the asymmetricaddition of arylboronicacids to aryl aldehydes, providing a series of chiral diarylmethanols in excellent yields and enantioselectivities (up to 92% ee). Preliminary study has shown that this process is catalyzed by a Ru complex with a single monophosphorus ligand.
Isosterically designed chiral catalysts: Rationale, optimization and their application in enantioselective nucleophilic addition to aldehydes
作者:En Gao、Qiao Li、Lili Duan、Lin Li、Yue-Ming Li
DOI:10.1016/j.tet.2020.131648
日期:2020.11
enantioselective nucleophilic addition to aldehydes. In the presence of 10 mol% of chiral ligand 1b, enantioselective addition of diethylzinc to aldehydes provided the corresponding secondary alcohols in up to 90% isolated yield and up to 99% ee. Similarly, using 3e as chiral ligand, enantioselective arylation and alkynylation of aldehydes also proceeded readily, leading to the desired chiral alcohols in up to
directing group (bromo group) showcased the potential application of this substrate‐controlled bioreduction reaction. The combined use of substrateengineering and protein engineering, was demonstrated to be a useful strategy in efficiently improving stereoselectivity or switching stereopreference of enzymatic processes.
Remarkably Efficient Enantioselective Titanium(IV)−(<i>R</i>)-H<sub>8</sub>-BINOLate Catalyst for Arylations to Aldehydes by Triaryl(tetrahydrofuran)aluminum Reagents
作者:Kuo-Hui Wu、Han-Mou Gau
DOI:10.1021/ja062080y
日期:2006.11.1
Novel asymmetric triarylaluminum AlAr3(THF) additions to aldehydescatalyzed by 10 mol % of the titanium(IV) complex of (R)-H8-BINOL ligand are reported. The catalytic system is extremely efficient with reactions completing within 10 min. The system applies to the most diversified aldehydes to date, and more than 20 aldehydes were examined to afford diarylmethanols having an electron-donating or an
Evaluation of Enantiopure <i>N</i>-(Ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol for Catalytic Asymmetric Addition of Organozinc Reagents to Aldehydes
作者:Min-Can Wang、Qing-Jian Zhang、Wen-Xian Zhao、Xiao-Dan Wang、Xue Ding、Tao-Tao Jing、Mao-Ping Song
DOI:10.1021/jo701943x
日期:2008.1.1
catalytic asymmetric addition of organozinc reagents to aldehydes. The asymmetric ethylation, methylation, arylation, and alkynylation of aldehydes achieved enantioselectivity of up to 98.4%, 94.1%, 99.0%, and 84.6% ee, respectively, in the presence of a catalytic amount of chiral N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol. Our results demonstrated further that the four-membered heterocycle-based