CBZ6 as a Recyclable Organic Photoreductant for Pinacol Coupling
作者:Hua Wang、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.orglett.1c00537
日期:2021.4.16
% CBZ6)-catalyzed reductive (pinacol) coupling of aldehydes, ketones, and imines has been developed. Irradiated by purple light (407 nm) using triethylamine as an electron donor, a variety of 1,2-diols and 1,2-diamines could be prepared. The oxidation potential of the excited state of CBZ6 is established as −1.92 V (vs saturated calomel electrode (SCE)). The relative high reductive potential enables
Treatment of aromatic carbonyl compounds with Zn powder in 10% aq NaOH solution without using any organic solvents under the mild conditions afforded the corresponding 1,2-diols in good yields.
Truly Catalytic and Enantioselective Pinacol Coupling of Aryl Aldehydes Mediated by Chiral Ti(III) Complexes<sup>†</sup>
作者:A. Chatterjee、T. H. Bennur、N. N. Joshi
DOI:10.1021/jo0342875
日期:2003.7.1
A variety of chiral Ti(IV) complexes were reduced in situ with zinc in acetonitrile. The resulting chiral Ti(III) complexes were found to catalyze the pinacol coupling reaction stereoselectively. The best results were obtained from the Ti-SALEN complex, which was found to be an efficient catalyst at 10 mol % concentration. Various aromatic aldehydes were coupled to obtain chiral hydrobenzoin derivatives
Facile pinacol coupling of aliphatic ketones by Brook rearrangement in the presence of samarium species
作者:Xincan Wang、Guanqun Xie、Yanfei Zhao、Ke Zheng、Yanxiong Fang、Xiaoxia Wang
DOI:10.1016/j.tetlet.2021.153069
日期:2021.5
Herein we report a practical pinacol coupling reaction, in which ketones (aldehydes) react smoothly with Sm and TMSBr to afford the diol products with Sm(II) or (III) siliyl species generated in situ. This reported method affords poor yields for aromatic ketone substrates and good yields for aliphaticketones. Therefore, it distinguishes from most reductive coupling approaches that are more effective for