27693-60-3Relevant academic research and scientific papers
Ligand-Free Iridium-Catalyzed Dehydrogenative ortho C?H Borylation of Benzyl-2-Pyridines at Room Temperature
Yang, Yuhuan,Gao, Qian,Xu, Senmiao
supporting information, p. 858 - 862 (2019/01/04)
A convenient and ligand-free iridium-catalyzed dehydrogenative ortho C?H borylation of benzyl-2-pyridines has been developed. The reaction proceeds smoothly at room temperature using pinacolborane as a borylating reagent in the presence of catalytic amount of [IrOMe(COD)]2. The reaction is compatible with many functional groups, providing a vast array of ortho borylated products in moderate to excellent yields with excellent selectivities. (Figure presented.).
Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N-Heteroaryl Ketones with N-Oxide as a Removable ortho-Substituent
Liu, Qixing,Wang, Chunqin,Zhou, Haifeng,Wang, Baigui,Lv, Jinliang,Cao, Lu,Fu, Yigang
, p. 971 - 974 (2018/02/23)
A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and sodium formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee.
Nickel-Catalyzed Hydrogenolysis and Conjugate Addition of 2-(Hydroxymethyl)pyridines via Organozinc Intermediates
Hanna, Luke E.,Harris, Michael R.,Domon, Kenji,Jarvo, Elizabeth R.
supporting information, p. 6304 - 6307 (2017/12/08)
2-Hydroxymethylpyridines undergo nickel-catalyzed hydrogenolysis upon activation with a chlorophosphate. Reactions employ diethylzinc and are proposed to proceed through secondary benzylzinc reagents. Quenching with deuteromethanol provides straightforward incorporation of a deuterium label in the benzylic position. Intramolecular conjugate additions with α,β-unsaturated esters are also demonstrated and support the intermediacy of a benzylzinc complex.
Convenient, benign and scalable synthesis of 2- and 4-substituted benzylpiperidines
Agai, Bela,Proszenyak, Agnes,Tarkanyi, Gabor,Vida, Laszlo,Faigl, Ferenc
, p. 3623 - 3632 (2007/10/03)
A short, scalable and environmentally benign synthesis of 2- and 4-substituted benzylpiperidines has been developed. The method is based on the temperature-programmed consecutive deoxygenation and heteroaromatic ring saturation of aryl(pyridin-2-yl)- and aryl(pyridin-4-yl)methanols and aryl(pyridin-4-yl)methanones in the presence of Pd/C catalyst. The crucial roles of the temperature, the acidity and the substrate structure in the change of selectivity have been demonstrated by isolation of several substituted aryl(piperidine)methanols. The carbinols and ketones were prepared from commercially available pyridinecarbaldehydes or 4-cyanopyridine and substituted bromobenzenes via organometallic intermediates. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
