18228-44-9Relevant articles and documents
The chromium(II)-mediated coupling of secondary alkylhalides with aromatic aldehydes
Wessjohann, Ludger A.,Schmidt, Gisela,Schrekker, Henri S.
, p. 2139 - 2141 (2007)
The scope of chromium(II)-mediated Takai-Utimoto reactions was extended to previously unconvertable secondary alkylhalides. Optimization allowed yields of up to over 95%. Georg Thieme Verlag Stuttgart.
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.].
Ruthenium(II)-Catalyzed β-Methylation of Alcohols using Methanol as C1 Source
Kaithal, Akash,Schmitz, Marc,H?lscher, Markus,Leitner, Walter
, p. 5287 - 5291 (2019/05/28)
Selective introduction of methyl branches into the carbon chains of alcohols can be achieved with low loadings of ruthenium precatalyst [RuH(CO)(BH4)(HN(C2H4PPh2)2)] (Ru-MACHO-BH) using methanol both as methylating reagent and as reaction medium. A wide range of structurally divers alcohols was β-methylated with excellent selectivity (>99 %) in fair to high yields (up to 94 %) under standard conditions, and turnover numbers up to 18,000 could be established. The overall reaction rate of the complex catalytic network appears to be governed by interconnection of the individual subcycles through availability of the reactive intermediates. The synthetic procedure opens pathways to important structural motifs following the Green Chemistry principles.