74105-54-7

Upstream product

• 74105-62-7 4-[(9H-Fluoren-9-ylmethoxycarbonyl)-hydrazonomethyl]-benzoic acid methyl ester 
• 1571-08-0 methyl 4-formylbenzoate 

Downstream Products

• 38145-01-6 dimethyl 4,4'-(hydrazine-1,2-diylidenebis(methanylylidene))dibenzoate 
• 842141-96-2 methyl 4-(3-bromo-2,2,3,3-tetrafluoropropyl)benzoate 
• 1226600-38-9 methyl (Z)-4-(2,3,3,3-tetrafluoroprop-1-en-1-yl)benzoate 
• 444915-76-8 methyl 4-(difluoromethyl)benzoate 
• 99846-96-5 methyl 4-α,α-dichloromethylbenzoate 
• 1254114-69-6 methyl 4-(2’,2’,2’-trifluoroethyl)benzoate 
• 15451-34-0 4-(3-buten-1-yl)benzoic acid methyl ester 
• 22744-12-3 [4-(methoxycarbonyl)phenyl]acetic acid 
• 23450-30-8 methyl 4-benzylbenzoate 
• 64299-49-6 4-(fluoromethyl)benzoic acid methyl ester 

Relevant academic research and scientific papers

Cross-Coupling of Phenol Derivatives with Umpolung Aldehydes Catalyzed by Nickel

A nickel-catalyzed cross-coupling to construct the C(sp2)-C(sp3) bond was developed from two sustainable biomass-based feedstocks: phenol derivatives with umpolung aldehydes. This strategy features the in situ generation of moisture/air-stable hydrazones from naturally abundant aldehydes, which act as alkyl nucleophiles under catalysis to couple with readily available phenol derivatives. The avoidance of using both halides as the electrophiles and organometallic or organoboron reagents (also derived from halides) as the nucleophiles makes this method more sustainable. Water tolerance, great functional group (ketone, ester, free amine, amide, etc.) compatibility, and late-stage elaboration of complex biological molecules exemplified its practicability and unique chemoselectivity over organometallic reagents.

Addition reactions of organic carbanion equivalents via hydrazones in water

The addition of organometallic reagents to unsaturated bonds is one of the most powerful tools for carbon–carbon bond formations. Alkylation through organometallic reagents requires stoichiometric quantity of metal and tedious anhydrous operation in most cases. Here, we report “umpolung” nucleophilic additions of hydrazones to Michael acceptors, carbonyls and imines in water. Under the catalysis of ruthenium(II), the addition reactions could be carried out in pure water to provide various alkylation products in moderate to good yields.

Palladium-Catalyzed Defluorinative Alkylation of gem-Difluorocyclopropanes: Switching Regioselectivity via Simple Hydrazones

Conventional approaches for Pd-catalyzed ring-opening cross-couplings of gem-difluorocyclopropanes with nucleophiles predominantly deliver the β-fluoroalkene scaffolds (linear selectivity). Herein, we report a cooperative strategy that can completely switch the reaction selectivity to give the alkylated α-fluoroalkene skeletons (branched selectivity). The unique reactivity of hydrazones that enables analogous inner-sphere 3,3′-reductive elimination driven by denitrogenation, as well as the assistance of steric-embedded N-heterocyclic carbene ligand, are the key to switch the regioselectivity. A wide range of hydrazones derived from naturally abundant aryl and alkyl aldehydes are well applicable, and various gem-difluorocyclopropanes, including modified pharmaceutical and biological molecules, can be efficiently functionalized with high value alkylated α-fluorinated alkene motifs under mild conditions.

Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones

Copper-catalyzed conjugate addition is a classic method for forming new carbon-carbon bonds. However, copper has never showed catalytic activity for umpolung carbanions in hydrazone chemistry. Herein, we report a facile conjugate addition of hydrazone catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentate ligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.

Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2-Trifluoroethyl)arenes

Reacting hydrazones of arylaldehydes with Togni's CF3-benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal-free.

Metal-Free Construction of the C(sp3)-CF3 Bond: Trifluoromethylation of Hydrazones with Togni's Reagent under Mild Conditions

A metal-free trifluoromethylation of hydrazones with Togni's reagent under mild conditions was developed. Various functional groups including ester, methoxy, dimethoxy, nitro, halogen, and heterocyclic compounds were tolerated. This simple and green strategy provides a practical tool to construct C(sp3)-CF3 bonds.

Umpolung cross-coupling of polyfluoroarenes with hydrazones: Via activation of C-F bonds

An umpolung strategy for the cross-coupling of polyfluoroarenes with various substituted hydrazones to construct C(sp2)-C(sp3) bonds is developed. In this strategy, the C-F bond of polyfluoroarenes is cleaved and coupled with moisture- and air-stable hydrazones under mild conditions with good to excellent yields. This method provides a useful tool for synthesizing polyfluorinated pharmaceuticals and functional materials.

Green, Catalyst-Free Reaction of Indoles with β-Fluoro-β-nitrostyrenes in Water

The reaction of 2-fluoro-2-nitrostyrenes with various indoles was investigated. We found that the reaction proceeds as a Michael addition in a highly regioselective manner to form 3-(1-aryl-2-fluoro-2-nitroethyl)-1H-indoles. Thus, a green and catalyst-free synthesis of these compounds was developed using water as a reaction medium. The high effectiveness of this approach was demonstrated through the preparation of target products in up to 92 % isolated yield. Subsequent reduction of the nitro group was investigated. We found that due to the instability of the intermediate α-fluoro amines, the reduction led to non-fluorinated tryptamine derivatives.

Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation

Palladium-catalyzed allylic alkylation of nonstabilized carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallic reagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not only from aryl aldehydes but also from alkyl aldehydes and ketones as renewable feedstocks. This strategy complements the palladium-catalyzed coupling of unstabilized nucleophiles with allylic electrophiles by providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.

Synthesis of Aryldihalomethanes by Denitrogenative Dihalogenation of Benzaldehyde Hydrazones

We report a denitrogenative dihalogenation reaction of phenyldiazomethanes in which the hypervalent iodine reagents PhICl2 and TolIF2 act as surrogates for elemental chlorine and fluorine. Halogen transfer from iodane to aryldiazomethane is described, as is a tandem oxidative dihalogenation reaction between iodane and hydrazone. This is the first use of non-α-stabilized diazo compounds in this reaction, which provided an efficient synthesis of aryldifluoromethane (ArCHF2) and aryldichloromethane (ArCHCl2) derivatives. (Figure presented.).