3968-86-3Relevant articles and documents
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.].
Diamine-free lithiation-trapping of N-Boc heterocycles using s-BuLi in THF
Barker, Graeme,Obrien, Peter,Campos, Kevin R.
supporting information; experimental part, p. 4176 - 4179 (2010/11/16)
A diamine-free protocol for the s-BuLi-mediated lithiation-trapping of N-Boc heterocycles has been developed. In the optimized procedure, lithiation is accomplished using s-BuLi in THF at -30 °C for only 5 or 10 min. Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered a range of functionalized pyrrolidines, imidazolidines, and piperazines in 43-83% yield.
The chromium(II)-mediated coupling of secondary alkylhalides with aromatic aldehydes
Wessjohann, Ludger A.,Schmidt, Gisela,Schrekker, Henri S.
, p. 2139 - 2141 (2008/02/09)
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.
