94474-89-2Relevant academic research and scientific papers
Highly efficient NHC-iridium-catalyzed β-methylation of alcohols with methanol at low catalyst loadings
Lu, Zeye,Zheng, Qingshu,Zeng, Guangkuo,Kuang, Yunyan,Clark, James H.,Tu, Tao
, p. 1361 - 1366 (2021/06/30)
The methylation of alcohols is of great importance since a broad number of bioactive and pharmaceutical alcohols contain methyl groups. Here, a highly efficient β-methylation of primary and secondary alcohols with methanol has been achieved by using bis-N-heterocyclic carbene iridium (bis-NHC-Ir) complexes. Broad substrate scope and up to quantitative yields were achieved at low catalyst loadings with only hydrogen and water as by-products. The protocol was readily extended to the β-alkylation of alcohols with several primary alcohols. Control experiments, along with DFT calculations and crystallographic studies, revealed that the ligand effect is critical to their excellent catalytic performance, shedding light on more challenging Guerbet reactions with simple alcohols. [Figure not available: see fulltext.].
THE EFFECT OF para-SUBSTITUENTS ON THE CONFORMATIONAL BEHAVIOUR OF AROMATIC SIDECHAINS
Cook, Michael J.,Khan, Tauqeer A.,Nasri, Khalida
, p. 249 - 258 (2007/10/02)
Proton nmr data are reported for some 2-aryl-1-propyl methyl esters, 2-aryl-1-propyl acetates and trifluoroacetates, 2-aryl-1-propanols and 4-aryl-2,2-dimethylpentanes.The vicinal coupling constants show that there is an increasing population of gauche Aryl/OR rotamers in the first three series (R = Me, R = COMe and R = COCF3) as electron donor groups on the aromatic ring are replaced by electron withdrawing groups.The results are ascribed to a gauche Aryl --- O interaction, the possible origins of which are discussed.
