129197-02-0Relevant academic research and scientific papers
Transition-Metal Free Chemoselective Hydroxylation and Hydroxylation-Deuteration of Heterobenzylic Methylenes
Fu, Yiwei,Li, Hao,Liu, Yonghai,Mang, Zhiguo,Shi, Lei,Sun, Chengyu,Yu, Yang
supporting information, p. 8127 - 8131 (2020/11/03)
We developed an approach for direct selective hydroxylation of heterobenzylic methylenes to secondary alcohols avoiding overoxidation to ketones by using a KOBu-t/DMSO/air system. Most reactions could reach completion in several minutes to give hydroxylated products in 41-76% yields. Using DMSO-d6, this protocol resulted in difunctionalization of heterobenzylic methylenes to afford α-deuterated secondary alcohols (>93% incorporation). By employing this method, active pharmaceutical ingredients carbinoxamine and doxylamine were synthesized in two steps in moderate yields.
Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands
Tole, Tegene T.,Jordaan, Johan H.L.,Vosloo, Hermanus C.M.
, p. 194 - 209 (2019/02/20)
Four new Grubbs-type precatalysts [RuCl(H2IMes)(O^N)(=CHPh)], where [O^N = α,α-diphenyl-(3-methylpyridin-2-yl)methanolato, α,α-diphenyl-(4-methylpyridin-2-yl)methanolato, α,α-diphenyl-(5-methylpyridin-2-yl)methanolato and α,α-diphenyl-(3-methoxypyridin-2-yl)methanolato] were synthesized and tested for their activity, stability and selectivity in the 1-octene metathesis reaction. Overall the precatalysts showed good activity and high stability for the metathesis of 1-octene at temperatures above 80 °C and up to 110 °C. Selectivities towards the primary metathesis products, i.e., 7-tetradecene and ethene, above 85% were obtained with all the precatalysts at 80 and 90 °C. High selectivities were also observed at 100 °C for the 4-Me- and 3-OMe-substituted precatalysts. With an increase in temperature an increase in isomerisation products and secondary metathesis products were observed with the latter reaching values >20% for the 3-OMe- and 3-Me-substituted precatalysts at 110 and 100 °C, respectively. All the precatalysts exhibits first-order kinetics at 80 °C with the 3-substituted precatalysts the slowest. The behaviour of the 3-substituted precatalysts can be attributed to electronic and steric effects associated with the adjacent bulky phenyl groups.
Complex-induced proximity effect in the regioselective lithiation of pyridine derivatives
Dhau, Jaspreet S.,Singh, Amritpal,Kasetti, Yoganjaneyulu,Bharatam
experimental part, p. 1746 - 1752 (2012/05/04)
The regioselective ring lithiation of BF3-complexed 3-picoline (1a), 3,4-lutidine (1b), and 3,5-lutidine (1c) was studied. The dilithiation of 1a, 1b, and 1c was also investigated to experimentally explore the relative preference of the sites on the substituted pyridine ring for lithiation. The role of the complex-induced proximity effect (CIPE) for inducing lithiation in these moieties was investigated using both experimental and computational studies.
DIPHENYLHYDROXYMETHYLATION OF 3-METHYLPYRIDINE N-OXIDE BY THE DIANIONS OF BENZHYDROL AND THE KETYLS OF BENZOPHENONE
Kurbatova, A. S.,Kurbatov, Yu. V.,Niyazova, D. A.
, p. 557 - 559 (2007/10/02)
The reaction of 3-methylpyridine N-oxide with with the disodium, dipotassium, and dilithium salts of benzhydrol, generated from benzophenone and two moles of the respective metal, and the analogous ketyls of benzophenone leads to the products from diphenylhydroxymethylation in the side chain and in the ring and also the product from deoxidation (3-methylpyridine)
