A Convenient Method for the Regioselective Synthesis of 4-Alkyl(aryl)pyridines Using Pyridinium Salts
作者:Kin-ya Akiba、Y\={u}ji Iseki、Makoto Wada
DOI:10.1246/bcsj.57.1994
日期:1984.7
(81–94%). The dihydropyridines were oxidized by oxygen to give 4-alkyl(aryl)pyridines (38–68%). Grignardreagents also reacted with 1-t-butyldimethylsilylpyridinium triflate with almost complete regioselectivity (>99%) to afford the corresponding 1,4-dihydropyridines, which were easily oxidized by oxygen to give 4-substituted pyridines in higher yields than above (58–70%).
Zn-promoted regio- and sequence-selective one-pot joining reactions of three components: vinylpyridines, alkyl iodides, and carbonyl compounds (or nitriles)
of alkyliodides (3) into the solution containing 2-(or 4-)vinylpyridine (1 or 2) and carbonyl compounds (6) in the presence of Zn-powder (99.9%) in acetonitrile under refluxing brought about regio- and sequence-selective joining reaction of three components to give the corresponding (2-hydroxyethyl)pyridines (7 or 8) in good to moderate yields. On the other hand, 2-(2- or 4-pyridyl)ethyl alkyl ketones
PROCESS FOR PRODUCTION OF BIS-QUATERNARY AMMONIUM SALT, AND NOVEL INTERMEDIATE
申请人:Okamoto Kuniaki
公开号:US20120130107A1
公开(公告)日:2012-05-24
Object To provide a method for producing a bis-quaternary ammonium salt efficiently and a novel synthetic intermediate thereof.
Solution The present invention relates to a method for producing a bis-quaternary ammonium salt represented by a general formula [3] which comprises reacting a disulfonic acid ester represented by a general formula [1] (in the formula, definitions of two R
1
's and T are as described in claim
1
) with a tertiary amine represented by a general formula [2] (in the formula, definitions of R
3
to R
5
are as described in claim
1
), and a disulfonic acid ester represented by a general formula [1′] (in the formula, two R
16
's represent independently a halogen atom or a C1-C3 fluoroalkyl group, and two m's represent independently an integer of 1 to 5).
How pyridine got its tail: A new catalyst for the atom‐economical C4‐selective direct alkylation of pyridines is described. A combination of CoBr2 and LiBEt3H catalyzes the reaction of pyridines with 1‐alkenes at 70 °C to give alkylation products with C4/C2 ratios of >20:1. Substrate/catalyst ratios of up to 4000, and a turnover number of 3440 were achieved.
Synthesis and Utility of Dihydropyridine Boronic Esters
作者:Santanu Panda、Aaron Coffin、Q. Nhu Nguyen、Dean J. Tantillo、Joseph M. Ready
DOI:10.1002/anie.201510027
日期:2016.2.5
When activated by an acylating agent, pyridine boronicesters react with organometallic reagents to form a dihydropyridineboronicester. This intermediate allows access to a number of valuable substituted pyridine, dihydropyridine, and piperidine products.