13683-85-7

Upstream product

• 110-89-4 piperidine 
• 637-69-4 4-Methoxystyrene 
• 81860-76-6 2-(4-methoxyphenyl)-1-(piperidin-1-yl)ethan-1-one 
• 702-23-8 2-(4-Methoxyphenyl)ethanol 
• 104-01-8 4-Methoxyphenylacetic acid 
• 768-60-5 4-methoxyphenylacetylen 

Downstream Products

• 82966-18-5 1-(4-methoxyphenethyl)-piperidine 

Relevant academic research and scientific papers

Facile preparation of pyrimidinediones and thioacrylamides: Via reductive functionalization of amides

The development of an efficient protocol for the reductive functionalization of amides into pyrimidinediones and amino-substituted thioacrylamides is presented. Enamines are generated in a highly chemoselective amide hydrosilylation reaction catalyzed by

Transformation of Amides into Highly Functionalized Triazolines

Triazoles and triazolines are important classes of heterocyclic compounds known to exhibit biological activity. Significant focus has been given to the development of synthetic approaches for the preparation of triazoles, and they are today easily obtainable through a large variety of protocols. The number of synthetic procedures for the formation of triazolines, on the other hand, is limited and further research in this field is required. The protocol presented here gives access to a broad scope of 1,4,5-substituted 1,2,3-triazolines through a one-pot transformation of carboxamides. The two-step procedure involves a Mo(CO)6-catalyzed reduction of tertiary amides to afford the corresponding enamines, followed by in situ cycloaddition of organic azides to form triazolines. The amide reduction is chemoselective and allows for a wide variety of functional groups such as esters, ketones, aldehydes, and imines to be tolerated. Furthermore, a modification of this one-pot procedure gives access to the corresponding triazoles. The chemically stable amide functionality is demonstrated to be an efficient synthetic handle for the formation of highly substituted triazolines or triazoles.

SmI2(H2O)n Reduction of Electron Rich Enamines by Proton-Coupled Electron Transfer

Samarium diiodide in the presence of water and THF (SmI2(H2O)n) has in recent years become a versatile and useful reagent, mainly for reducing carbonyl-type substrates. This work reports the reduction of several enamines by SmI2(H2O)n. Mechanistic experiments implicate a concerted proton-coupled electron transfer (PCET) pathway, based on various pieces of evidence against initial outer-sphere electron transfer, proton transfer, or substrate coordination. A thermochemical analysis indicates that the C-H bond formed in the rate-determining step has a bond dissociation free energy (BDFE) of ～32 kcal mol-1. The O-H BDFE of the samarium aquo ion is estimated to be 26 kcal mol-1, which is among the weakest known X-H bonds of stable reagents. Thus, SmI2(H2O)n should be able to form very weak C-H bonds. The reduction of these highly electron rich substrates by SmI2(H2O)n shows that this reagent is a very strong hydrogen atom donor as well as an outer-sphere reductant.

Catalytic reductive dehydration of tertiary amides to enamines under hydrosilylation conditions

Tertiary amides are efficiently reduced to their corresponding enamines under hydrosilylation conditions, using a transition-metal-free catalytic protocol based on t-BuOK (5 mol %) and (MeO)3SiH or (EtO) 3SiH as the reducing agent. The enamines were formed with high selectivity in good-to-excellent yields.

Mechanistic Studies on the Catalytic Oxidative Amination of Alkenes by Rhodium(I) Complexes with Hemilabile Phosphines

Cationic rhodium(I) complexes with P,O-functionalised arylphosphine ligands are efficient catalysts for the regioselective anti-Markovnikov oxidative amination of styrene with piperidine. The mechanism of the catalytic reaction has been investigated by spectroscopic means under stoichiometric and catalytic conditions. In the presence of piperidine, the catalyst precursor [Rh{κ2-P,O-Ph2P(CH2)3OEt}2]+ (5) gave the piperidine complex [Rh{κ1-P-Ph2P(CH2)3OEt}2(HNC5H10)2]+ (8) that was transformed into the neutral amido-piperidine species [Rh{κ1-P-Ph2P(CH2)3OEt}2(NC5H10)(HNC5H10)] (9) under thermal conditions. NMR studies performed in the presence of styrene under catalytic conditions showed that 9 is a key species in the catalytic oxidative amination of styrene. Related cyclooctadiene-containing catalyst precursors [Rh(cod){κ1-P-Ph2P(CH2)3OEt}n]+ (n=1, 2) also gave 9 under the same conditions. The proposed catalytic cycle has been established by a series of DFT calculations including the transition states of the key steps that have been identified and characterised. These studies have shown that, after elimination of the enamine, regeneration of catalytic active species takes place by direct transfer of the proton of a piperidine ligand to the alkyl group resulting from the insertion of styrene into the Rh-H bond and formation of ethylbenzene. Against the expectations, the formation of a dihydride intermediate by NH oxidative addition is a highly energy-demanding process. Catalyst 5 has also been applied for the oxidative amination of substituted vinylarenes with several secondary cyclic and acyclic amines.

Rhodium-catalyzed anti-markovnikov addition of secondary amines to arylacetylenes at room temperature

An efficient method for synthesis of E-enamines by the anti-Markovnikov addition of secondary amines to terminal alkynes is described. The reaction of a variety of aryl- and heteroarylacetylenes proceeded at room temperature using a combination of a 8-quinolinolato rhodium complex and P(p-MeOC6H 4)3 as a catalyst. The products were obtained as enamines by simple bulb-to-bulb distillation.