69770-00-9Relevant articles and documents
Regioselectivity of Cobalamin-Dependent Methyltransferase Can Be Tuned by Reaction Conditions and Substrate
Pompei, Simona,Grimm, Christopher,Farnberger, Judith E.,Schober, Lukas,Kroutil, Wolfgang
, p. 5977 - 5983 (2020/10/06)
Regioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4-substituted catechols was investigated employing the cobalamin-dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta- or para-position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta-selective with 4-substituted catechols bearing hydrophilic groups, it was para-selective for hydrophobic substituents. Furthermore, the presence of water miscible co-solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
Direct oxidation of the C(sp2)-C(sp3) bond from benzyltrimethylsilanes to phenols
Li, Wei,Gao, Guolin,Gao, Yuan,Yang, Chao,Xia, Wujiong
supporting information, p. 5291 - 5293 (2017/07/10)
A novel pathway for direct conversion of benzylsilanes to phenols by oxidation with Na2S2O8 and oxygen is efficiently developed under mild and neutral conditions. The reaction shows good functional group tolerance to afford phenols in moderate yields. The possible mechanism is proposed based on the isotopic labeling trials.
HETEROCYCLIC NON-PEPTIDE GNRH ANTAGONISTS
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Page/Page column 66, (2008/06/13)
A compound of formula (I): wherein either B is absent and A and Z are the same or different and are each hydrogen, halogen, alkyl, hydroxy, alkoxy,-CN,-C(Rc)2OH,-N(Rd)C(=X)Rc,-C(=X)N(Rc)(Rd),-S(O)m-Rc,-N(Rc)(Rd)S(O)2,-S(O)2N(R c)(Rd),-N(Re)2, aryl optionally substituted with Ra or-O-aryl optionally substituted with Ra; or B is present and is-(CH2)n-,-C(Rb)2-or-O-, or B taken together with A or Z can be-C=C(Rb)-,-C(Rb)=C-,-CH2-CH(R b)-or-CH(Rb)-CH2-; D is-O-or-S(O) m,-; E is a bond or is-(CH2)n-,-N(R d)-,-(CH2)nN(Rd)-or-N(R d)(CH2)n-; F is-C(=X)-; G is-(CH2 )n-,-N(Rd)-,-(CH2)nN(R d)-or-N(Rd)(CH2)n; J is a bond,-O-,-N(RC)C(=X)-,-C(=X)N(Rc)-,-S(O)m,-,-N(Rc)S(O)m-,-S(O)nN(Rc)-,-N(Re)-or-N(Rg)(Rh); K is a bond, alkylene, cycloalkylene, cycloalkenylene, arylene, heterocycloalkylene, heterocycloalkylene or heteroarylene; and L is hydrogen or a terminal group; has therapeutic utility.
Facile and regioselective dealkylation of alkyl aryl ethers using niobium(V) pentachloride
Sudo, Yukinori,Arai, Shigeru,Nishida, Atsushi
, p. 752 - 758 (2007/10/03)
A simple and facile method for the cleavage of carbon-oxygen bonds promoted by niobium pentachloride(V) is described. Excellent yields and regioselectivities were observed with various alkyl aryl ethers to give the phenols. NMR studies revealed the formation of monoaryloxy niobium salt(V), and a neighboring-group effect may play a significant role in the regioselectivity. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
O-Methylation of tert-Alkylpyrocatecholes. Analytical Method for Determination of the Content of Product Mixtures and Way for Preparation of 4-tert-Alkylveratroles
Beger, J.,Meerbote, M.
, p. 119 - 125 (2007/10/02)
The O-methylation of tert-alkylpyrocatecholes with dimethylsulfate leads to a mixture of substituted guaiacoles 6/7, 9/10 and veratroles 5, 6 which are separated by gas/liquid-chromatography for analytical purposes.It is also possible to prepare 4-tert-alkylsubstituted veratroles 5 with good yields in this way.On the other hand, the alkylation of veratrole was only successful with lower tert-alkanols or alkenes.Long-chained tert-alkanols fail in this reaction.The analytical and spectroscopical data of some new 4-tert-alkylveratroles 5a-g are given.
