51-67-2Relevant articles and documents
Singlet oxygen-responsive photorelease of tyramine
Jeong, Dong Yeun,Yi, Seung Yeon,You, Youngmin
, p. 1497 - 1500 (2021)
A system capable of photoreleasing tyramine has been developed. The photodonor system consists of an isoindole cage of tyramine and a biscyclometalated Ir(III) complex singlet oxygen (1O2) photosensitizer. Photoirradiation at a wavelength of 365 nm produces tyramine, as evidenced by mass spectrometry and 1H NMR spectroscopy. The photorelease proceeds through two steps involving the formation of a Diels–Alder-type [2 + 4] cycloadduct of 1O2, followed by the slow and spontaneous decomposition of the adduct into tyramine and 2-benzoylbenzophenon.
Kushimov et al.
, (1968)
The production of tyramine: Via the selective hydrogenation of 4-hydroxybenzyl cyanide over a carbon-supported palladium catalyst
McAllister, Mairi I.,Boulho, Cédric,McMillan, Liam,Gilpin, Lauren F.,Wiedbrauk, Sandra,Brennan, Colin,Lennon, David
, p. 29392 - 29399 (2018)
The selective production of primary amines is a problem that plagues heterogeneously catalysed nitrile hydrogenation reactions. Whilst the target amine tyramine (HOC6H4CH2CH2NH2) is biochemically available through the action of enzymes, synthetic routes to this species are not widely reported. Here, a heterogeneously catalysed method is proposed that utilises a Pd/C catalyst to effect the selective hydrogenation of 4-hydroxybenzyl cyanide within a three-phase reactor. The aforementioned selectivity issues are overcome by adjustment of various experimental parameters (hydrogen supply, agitation rate, temperature, use of an auxiliary agent) that result in improved catalytic performance, such that the desired tyramine salt (tyramine hydrogen sulphate) can be produced in quantitative yield. Accordingly, through consideration of the interconnectivity of hydrogenation and hydrogenolysis processes, a selective synthetic strategy is achieved with the findings suitable for extension to other substrates of this nature.
Multienzyme One-Pot Cascades Incorporating Methyltransferases for the Strategic Diversification of Tetrahydroisoquinoline Alkaloids
Andexer, Jennifer N.,Cárdenas-Fernández, Max,Hailes, Helen C.,Méndez-Sánchez, Daniel,Richter, Michael,Roddan, Rebecca,Siegrist, Jutta,Subrizi, Fabiana,Thair, Benjamin,Wang, Yu,Ward, John M.
supporting information, p. 18673 - 18679 (2021/07/19)
The tetrahydroisoquinoline (THIQ) ring system is present in a large variety of structurally diverse natural products exhibiting a wide range of biological activities. Routes to mimic the biosynthetic pathways to such alkaloids, by building cascade reactions in vitro, represents a successful strategy and can offer better stereoselectivities than traditional synthetic methods. S-Adenosylmethionine (SAM)-dependent methyltransferases are crucial in the biosynthesis and diversification of THIQs; however, their application is often limited in vitro by the high cost of SAM and low substrate scope. In this study, we describe the use of methyltransferases in vitro in multi-enzyme cascades, including for the generation of SAM in situ. Up to seven enzymes were used for the regioselective diversification of natural and non-natural THIQs on an enzymatic preparative scale. Regioselectivites of the methyltransferases were dependent on the group at C-1 and presence of fluorine in the THIQs. An interesting dual activity was also discovered for the catechol methyltransferases used, which were found to be able to regioselectively methylate two different catechols in a single molecule.
Biomimetic synthesis of galantamine: Via laccase/TEMPO mediated oxidative coupling
Baratto, Maria Camilla,Bizzarri, Bruno Mattia,Botta, Lorenzo,Pogni, Rebecca,Saladino, Raffaele,Zippilli, Claudio
, p. 10897 - 10903 (2020/03/27)
Laccase-mediated intramolecular oxidative radical coupling of N-formyl-2-bromo-O-methylnorbelladine afforded a novel and isolable spirocyclohexadienonic intermediate of galantamine. High yield and conversion of substrate were obtained in the presence of the redox mediator 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). This laccase procedure, with an overall yield of 34%, represents a scalable and environmentally friendly alternative to previously reported syntheses of galantamine based on the use of potassium ferricyanide as an unspecific radical coupling reagent.