1077-79-8Relevant articles and documents
Teflon AF-2400 mediated gas-liquid contact in continuous flow methoxycarbonylations and in-line FTIR measurement of CO concentration
Koos, Peter,Gross, Ulrike,Polyzos, Anastasios,O'Brien, Matthew,Baxendale, Ian,Ley, Steven V.
, p. 6903 - 6908 (2011)
We report on the development of a continuous flow process for the palladium catalysed methoxycarbonylation of aryl, heteroaromatic and vinyl iodides and an aryl bromide using a Teflon AF-2400 based Tube-in-Tube reactor to mediate the selective permeation of carbon monoxide into solution at elevated pressures. The low volume of pressurised gas within the reactor (5.6 mL) offers the potential for an enhanced safety profile compared to batch processes. We also present preliminary results for the use of in situ FTIR to measure solution concentrations of carbon monoxide and demonstrate the use of a second reactor to effect the removal of carbon monoxide from the flow stream.
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Fiorentino,M. et al.
, p. 173 - 175 (1976)
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Direct Synthesis of Chiral NH Lactams via Ru-Catalyzed Asymmetric Reductive Amination/Cyclization Cascade of Keto Acids/Esters
Shi, Yongjie,Tan, Xuefeng,Gao, Shuang,Zhang, Yao,Wang, Jingxin,Zhang, Xumu,Yin, Qin
supporting information, p. 2707 - 2713 (2020/03/30)
Lactams with a stereogenic center adjacent to the N atom have existed in many medicinal agents and bioactive alkaloids. Herein we report a broadly applicable synthesis of enantioenriched NH lactams through a one-pot asymmetric reductive amination/cyclization sequence of easily available keto acids/esters. Such cascade processes alleviate the demand for protecting group manipulations as well as intermediate purification. This strategy is capable of constructing enantioenriched lactams and benzo-lactams of a five-, six-, or seven-membered ring in generally high yield and with excellent enantioselectivities (up to 97% ee). Scalable and concise syntheses of key drug intermediates have further displayed the importance of this methodology.
Capturing Intermediates in the Reaction Catalyzed by NosN, a Class C Radical S-Adenosylmethionine Methylase Involved in the Biosynthesis of the Nosiheptide Side-Ring System
Wang, Bo,Lamattina, Joseph W.,Marshall, Savannah L.,Booker, Squire J.
supporting information, p. 5788 - 5797 (2019/04/17)
Nosiheptide is a ribosomally synthesized and post-translationally modified thiopeptide natural product that possesses antibacterial, anticancer, and immunosuppressive properties. It contains a bicyclic structure composed of a large macrocycle and a unique
Synthesis of (R)-3-methylphthalide by reductive cyclization of a 2-acylarylcarboxylate using the chiral boronic ester TarB-H and sodium borohydride
De Souza, Aline Aparecida Nunes,Taylor, Jason Guy
, p. 657 - 660 (2017/01/16)
Background: Phthalides are pervasive benzolactone structural frameworks in nature and have a broad profile of biological activities. Catalytic asymmetric reduction with the in situ lactonization of 2-acylarylcarboxylate compounds is an efficient strategy for chiral phthalide synthesis. The tartaric acid-derived reagent TarB-X is capable of mediating the asymmetric reduction of aromatic ketones using either LiBH4 or NaBH4 as the reductant. Up until now, the asymmetric reduction by Tarb- H/NaBH4 had not been applied to the synthesis of chiral phthalides. Methods: The requsite substrate, methyl 2-acetylbenzoate was obtained by a two step reaction starting from phthalic anhydride and maloninc acid. Tarb-H was obtained by treatment of L-(+)-tartaric acid with phenylboronic acid. The catalyst and NaBH4 were reacted with methyl 2-acetylbenzoate at room temperature for 1 h. The structure of (R)-3-Methylphthalide was established by NMR and mass spectrometry and its enantiomeric excess was determined by HPLC. The relative configuration was deduced by comparison of the optical rotation with data given in the literature. Results: (R)-3-Methylphthalide was obtained in moderte yield and high enantiomeric excess. Conclusion: (R)-3-methylphthalide was prepared in high enantiomeric excesses using an inexpensive and easily synthesized tartaric acid derived boronic ester (TarB-H) with sodium borohydride. The chiral phthalide was obtained in an open flask by reductive cyclization of a 2-acylarylcarboxylate.
