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.
Synthesis of new benzimidazolium salts and their application in the asymmetric arylation of aldehydes
作者:Wei-Ping He、Bi-Hui Zhou、Ya-Li Zhou、Xiang-Rong Li、Li-Mei Fan、Hao-Wen Shou、Jie Li
DOI:10.1016/j.tetlet.2016.06.023
日期:2016.7
precursor of N-heterocyclic carbene ligands, were designed and synthesized from 1,2-dibromobenzene. In situ prepared corresponding carbenes were tested in asymmetric Rh-catalyzed arylation of aromatic aldehydes, affording chiral diarylmethanols with high yields and moderate enantioselectivities.
Asymmetric additive-free aryl addition to aldehydes using perhydrobenzoxazines as ligands and boroxins as aryl source
作者:Rebeca Infante、Javier Nieto、Celia Andrés
DOI:10.1039/c1ob05717k
日期:——
A highly efficient enantioselective aryl addition to aldehydes using boroxins as aryl source and conformationally restricted perhydro-1,3-benzoxazines as ligands is reported. Both enantiomeric forms of chiral arylphenylmethanols and 1,1′-disubstituted diarylmethanols are afforded with excellent yields and enantioselectivities using the same ligand by means of an appropriate combination of boroxin and aromatic aldehyde. The enantiocontrol is not significantly influenced by electronic effects or steric hindrance, even with substituted boroxins. Very homogeneous ee's are reached when substituted arylboroxins are employed, without the use of any class of additive or pre-treatment.
Stereospecific Pd-Catalyzed Intermolecular C(sp<sup>3</sup>)-C(sp) Cross-Coupling of Diarylmethyl Carbonates and Terminal Alkynes Under Base-Free Conditions
作者:Sho Tabuchi、Koji Hirano、Masahiro Miura
DOI:10.1002/chem.201503647
日期:2015.11.16
A palladium‐catalyzed intermolecular decarboxylative C(sp3)–C(sp) coupling of diarylmethyl carbonates and terminalalkynes has been developed. The reaction proceeds smoothly under external base‐free conditions to deliver the corresponding alkynylated diarylmethanes with the liberation of CO2 and MeOH as the sole byproducts. Moreover, enantioenriched diarylmethyl carbonates are stereospecifically converted
Photoassisted Cobalt-Catalyzed Asymmetric Reductive Grignard-Type Addition of Aryl Iodides
作者:Xuan Jiang、Hao Jiang、Qian Yang、Ying Cheng、Liang-Qiu Lu、Jon A. Tunge、Wen-Jing Xiao
DOI:10.1021/jacs.2c02481
日期:2022.5.11
Grignard addition is one of the most important methods used for syntheses of alcohol compounds and has been known for over a hundred years. However, research on asymmetric catalysis relies on the use of organometallic nucleophiles. Here, we report the first visible-light-induced cobalt-catalyzed asymmetric reductive Grignard-type addition for synthesizing chiral benzyl alcohols (>50 examples, up to