82226-09-3

Upstream product

• 108-89-4 picoline 
• 100-52-7 benzaldehyde 
• 4926-28-7 2-Bromo-4-picoline 
• 6630-33-7 ortho-bromobenzaldehyde 
• 1003-67-4 4-methylpyridine-1-oxide 
• 5191-54-8 2-benzyl-4-methyl pyridine 
• 67-68-5 dimethyl sulfoxide 
• 108-86-1 bromobenzene 
• 1620-76-4 2-Cyano-4-methylpyridin 
• 18103-77-0 (4-methylpyridin-2-yl)(phenyl)methanone 

Relevant academic research and scientific papers

From Pyridine- N-oxides to 2-Functionalized Pyridines through Pyridyl Phosphonium Salts: An Umpolung Strategy

The reactions of pyridine-N-oxides with Ph3P under the developed conditions provide an unprecedented route to (pyridine-2-yl)phosphonium salts. Upon activation with DABCO, these salts readily serve as functionalized 2-pyridyl nucleophile equivalents. This umpolung strategy allows for the selective C2 functionalization of the pyridine ring with electrophiles, avoiding the generation and use of unstable organometallic reagents. The protocol operates at ambient temperature and tolerates sensitive functional groups, enabling the synthesis of otherwise challenging compounds.

Green synthesis method of polyaryl substituted methanol

The invention relates to a green synthesis method of polyaryl substituted methanol, in particular to a method for efficiently synthesizing polyaryl substituted methanol in a polar aprotic solvent under the condition of an oxidizing agent by taking polyaryl substituted methane as a raw material and alkali as an additive. The method provided by the invention is green and environment-friendly, avoids using expensive metal catalysts, and has the advantages of low cost, few reaction steps, short time, high yield and the like.

Transition-Metal Free Chemoselective Hydroxylation and Hydroxylation-Deuteration of Heterobenzylic Methylenes

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.

Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N-Heteroaryl Ketones with N-Oxide as a Removable ortho-Substituent

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.

Electrophilic reaction of N-Lewis acid and N-oxide Lewis acid complexes of 4-methylpyridines and their N-oxides through base-induced deprotonation

The comparative studies were carried out on the relative reactivity of4-methylpyridines, their N-oxides and their Lewis acid complexes towards electrophilic reaction. α-Deprotonation in pyridine ring rather than deprotonation of active methyl group or metal-halogen exchange occurred preferentially in the reaction of N- and N-oxides BF3 complexes with electrophile in the presence of LTMP-TMEDA in THF to give a -substituted-4-methylpyridines and their N-oxides.

Intramolecular radical additions to pyridines

Intramolecular 6-exolendo-trig and 5-exo-trig cyclisations of aryl radical intermediates to the α-, β- P- and γ-carbons of pyridine have been shown to be facile processes at neutral pH. The tether conjoining the radical donor to the pyridine plays an important role in determining the outcome of the reaction. When a Z-alkene is used as a tether, ortho-cyclisation proceeds in good yield. A more complex course is followed when a saturated two carbon tether is employed, leading to products derived from hydrogen atom abstraction, ipso-cyclisation and ortho-cyclisation pathways. All attempts to effect 5-exolendo-trig cyclisations failed. Tributyltin hydride, tris(trimethylsilyl)silane, tris(trimethylsilyl)germane and, in part, samarium(II) iodide can each be employed as mediators of the reaction.

Side-chain retention during lithiation of 4-picoline and 3,4-lutidine: Easy access to molecular diversity in pyridine series

The first direct ring-selective lithiation of 4-picoline and 3,4-lutidine has been achieved through the use of BuLi/LiDMAE aggregates to prevent the usual side-chain metallation. Several functionalities have been introduced at the C-2, C-6 and C-5 positions by ring-selective sequential lithiation, opening a simple and fast route to polysubstituted pyridine building blocks. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Lewis Acid Complexed Heteroatom Carbanions; Synthesis of some α-Pyridyl Alcohols

Metallation of BF3-pyridine complex with lithium tetramethylpiperidide (LTMP) in ether at -78 deg C, followed by reaction with carbonyl compounds, affords α-pyridyl alcohols in good yields.