5331-48-6Relevant articles and documents
Pillar[5]arenes with an introverted amino group: A hydrogen bonding tuning effect
Chen, Lei,Li, Zhiming,Chen, Zhenxia,Hou, Jun-Li
, p. 248 - 251 (2013)
Pillar[5]arenes with introverted amino groups were produced through aminolysis. X-ray analysis demonstrated that the intramolecular hydrogen bonding induced the amino group toward the inner space of the cavity. The kinetic studies and molecular modelings revealed that the hydrogen bonding also contributed to the acceleration of the aminolysis through stabilizing the intermediate.
Decarboxylative Ritter-Type Amination by Cooperative Iodine (I/III)─Boron Lewis Acid Catalysis
Narobe, Rok,Murugesan, Kathiravan,Schmid, Simon,K?nig, Burkhard
, p. 809 - 817 (2022/01/15)
Recent years have witnessed important progress in synthetic strategies exploiting the reactivity of carbocations via photochemical or electrochemical methods. Yet, most of the developed methods are limited in their scope to certain stabilized positions in molecules. Herein, we report a metal-free system based on the iodine (I/III) catalytic manifold, which gives access to carbenium ion intermediates also on electronically disfavored benzylic positions. The unusually high reactivity of the system stems from a complexation of iodine (III) intermediates with BF3. The synthetic utility of our decarboxylative Ritter-type amination protocol has been demonstrated by the functionalization of benzylic as well as aliphatic carboxylic acids, including late-stage modification of different pharmaceutical molecules. Notably, the amination of ketoprofen was performed on a gram scale. Detailed mechanistic investigations by kinetic analysis and control experiments suggest two mechanistic pathways.
Monoacylation of Symmetrical Diamines in Charge Microdroplets
Ansu-Gyeabourh, Emelia,Amoah, Enoch,Ganesa, Chandrashekar,Badu-Tawiah, Abraham K.
, p. 531 - 536 (2021/01/13)
Monoacylation of symmetrical diamine is achieved when the primary α,ω-diamines (carbon numbers n = 3, 5 and 12) are diluted in ethyl acetate, and the resultant mixture is electrosprayed across a 10 mm distance in ambient air toward a mass spectrometer. The N-acylated product is formed in charged microdroplets without acidifying and activating agents and in the absence of heat. This result provided an insight into the orientation of the amines in the droplets, suggesting that the ester is activated to react with the amine at the droplet surface due to the high abundance of protons at the air-droplet interface.
Metal-Free O-Selective Direct Acylation of Amino Alcohols Through Pseudo-Intramolecular Process
Yokoyama, Soichi,Shibauchi, Hiroshi,Asahara, Haruyasu,Nishiwaki, Nagatoshi
supporting information, p. 1125 - 1133 (2019/02/01)
Efficient α-aryl-β-keto ester acylation of amine accompanied by the elimination of ethyl phenylacetate was achieved owing to the pseudo-intramolecular process. The eliminated ethyl phenylacetate could be recycled by conversion into an α-aryl-β-keto ester upon treatment with an acyl chloride in the presence of lithium bis(trimethylsilyl)amide, by which the atom economy considerably increased. Acylation using an α-aryl-β-keto ester is highly sensitive to the bulkiness of the nucleophile, which facilitated the regioselective-acylation of the less hindered amino group in diamine without protecting the other. The transacylation of α-aryl-β-keto ester with N-alkylamino alcohol resulted in chemoselective O-acylation without protecting the amino group because the hydroxy group was attracted to the reaction site of the keto ester by forming an ammonium salt. Transacylation was demonstrated to be a practically useful tool for organic synthesis because this protocol can be conducted under mild conditions with simple manipulations in the absence of any additives such as metal catalyst and base.
