103-05-9Relevant articles and documents
1-Naphthylmethyl and 1-naphthylmethoxymethyl protecting groups: New members of the benzyl- and benzyloxymethyl-type family
Sato, Takuya,Joh, Yohei,Oishi, Tohru,Torikai, Kohei
, p. 2178 - 2181 (2017)
1-Naphthylmethyl (NAPI) and 1-naphthylmethoxymethyl (NAPOMI) protecting groups were developed as new members of the benzyl- and benzyloxymethyl-type family. NAPI and NAPOMI can be introduced under conventional conditions, such as NAPIBr/NaH/room temperature (rt), or NAPOMICl/i-Pr2EtN/rt. They can also be removed under conventional conditions, e.g., by dichlorodicyanobenzoquinone (DDQ)- or ceric ammonium nitrate (CAN)-mediated oxidation, or by hydrogenolysis. The specific advantages of these new protecting groups are: i) a less costly synthesis of NAPOMICl compared to NAPOMIICl, ii) the possibility to remove NAPOMII selectively in the presence of NAPOMI by DDQ-mediated oxidation, and iii) the compatibility with strong acids even in the presence of hard nucleophiles.
Palladium Catalyzed, Regioselective Reduction of 1,2-Epoxides by Ammonium Formate
Dragovich, Peter S.,Prins, Thomas, J.,Zhou, Ru
, p. 4922 - 4924 (1995)
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PHOTOLYSIS OF 2-PHENYLETHYL AND 4-PHENYL-1-BUTYL HALIDES IN ALCOHOLIC SOLVENTS
Bhalerao, V. K.,Nanjundiah, B. S.,Sonawane, H. R.,Nair, P. M.
, p. 1487 - 1496 (1986)
Photolysis of 2-phenylethyl bromide in the lower alcohols gave the corresponding carbinols and ethers as the main products.With 2-phenylethyl iodide, the products were almost exclusively of the latter type, while 4-phenyl-1-butyl halides gave n-butylbenzene, 4-phenyl-1-butene and tetralin.It is shown that each of these products may be assigned to an ionic or radical pathway and that both the nature of the sovent and the structure of the substrate affect the course of photolysis.There is a substrate dependent preference for specific reactions along pathways of both the radical and ionic types.The variations in product composition and distribution are rationalized in terms of the relative efficiencies furnished in these pathways for the relaxation of high energy intermediates produced in the initial stages of photolysis.Intervention by the phenyl group is more pronunced in the case of 2-phenylethyl halides than in the case of the higher homologues and more effective in the ionic pathway.
Synthesis and evaluation of 1,1,7,7-tetramethyl-9-azajulolidine (TMAJ) as a highly active derivative of N,N-dimethylaminopyridine
Tsutsumi, Tomohiro,Saitoh, Arisa,Kasai, Tomoyo,Chu, MengYue,Karanjit, Sangita,Nakayama, Atsushi,Namba, Kosuke
, (2020)
1,1,7,7-Tetramethyl-9-azajulolidine (TMAJ), which theoretical studies have suggested as a highly active DMAP analog, was synthesized for the first time. The catalytic activity of TMAJ was confirmed by the acetylation reactions of various tert-alcohols. TMAJ showed much higher catalytic activity than DMAP and one of the highest activity levels among the conventional DMAP analogs. These experimental results were in good agreement with the previous theoretical studies.
Synergistic Catalysis for the Umpolung Trifluoromethylthiolation of Tertiary Ethers
Xu, Wentao,Ma, Junyang,Yuan, Xiang-Ai,Dai, Jie,Xie, Jin,Zhu, Chengjian
, p. 10357 - 10361 (2018)
The first transition-metal-free, site-specific umpolung trifluoromethylthiolation of tertiary alkyl ethers has been developed, achieving the challenging tertiary C(sp3)–SCF3 coupling under redox-neutral conditions. The synergism of organophotocatalyst 4CzIPN and BINOL-based phosphorothiols can site-selectively cleave tertiary sp3 C(sp3)–O ether bonds in complex molecules initiated by a polarity-matching hydrogen-atom-transfer (HAT) event. The incorporation of several competing benzylic and methine C(sp3)?H bonds in alkyl ethers has little influence on the regioselectivity. Selective difluoromethylthiolation of C?O bonds has also been achieved. This represents not only an important step forward in trifluoromethylthiolation but also a promising means for site-selective C?O bond functionalization of unsymmetrical tertiary alkyl ethers.
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Salkind
, (1916)
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Electrocatalytic Oxidative Hydrofunctionalization Reactions of Alkenes via Co(II/III/IV) Cycle
Yang, Fan,Nie, Yi-Chen,Liu, Han-Yuan,Zhang, Lei,Mo, Fanyang,Zhu, Rong
, p. 2132 - 2137 (2022/02/10)
Here we disclose a general Co(II/III/IV) electrocatalytic platform for alkene functionalization. Driven by electricity, a set of the oxidative hydrofunctionalization reactions via hydrogen atom transfer were demonstrated without the need for stochiometric chemical oxidants. The scope of the reactions encompasses hydroalkoxylation, hydroacyloxylation, hydroarylation, semipinacol rearrangement, and deallylation. Mechanistic studies and stereochemical evidence support an ECEC process involving an electrochemically generated organocobalt(IV) intermediate. This work presents an example of reactivity space expansion in electrocatalysis in the VB12-system by going beyond the common oxidation states of Co(I/II/III).
Cu-catalyzed cross-coupling of benzylboronic esters and epoxides
Gierszal, Sophia G.,Barker, Timothy J.
supporting information, (2021/09/20)
A reaction between epoxides and benzylboronic acid pinacol esters is described. CuI was found to be an effective catalyst of this transformation upon activation of the benzylboronic ester with an alkyllithium reagent. The reaction was very efficient and a variety of substituted epoxides were found to be good substrates with good regioselectivity for substitution at the less substituted side of the epoxide. A reaction using an enantioenriched secondary benzylboronic ester was found to not be stereospecific.
Design, synthesis and biological evaluation of 8-(2-amino-1-hydroxyethyl)-6-hydroxy-1,4-benzoxazine-3(4H)-one derivatives as potent β2-adrenoceptor agonists
Yi, Ce,Xing, Gang,Wang, Siqi,Li, Xiaoran,Liu, Yichuang,Li, Jinyan,Lin, Bin,Woo, Anthony Yiu-Ho,Zhang, Yuyang,Pan, Li,Cheng, Maosheng
, (2019/11/26)
A series of β2-adrenoceptor agonists with an 8-(2-amino-1-hydroxyethyl)-6-hydroxy-1,4-benzoxazine-3(4H)-one moiety is presented. The stimulatory effects of the compounds on human β2-adrenoceptor and β1-adrenoceptor were characterized by a cell-based assay. Their smooth muscle relaxant activities were tested on isolated guinea pig trachea. Most of the compounds were found to be potent and selective agonists of the β2-adrenoceptor. One of the compounds, (R)-18c, possessed a strong β2-adrenoceptor agonistic effect with an EC50 value of 24 pM. It produced a full and potent airway smooth muscle relaxant effect same as olodaterol. Its onset of action was 3.5 min and its duration of action was more than 12 h in an in vitro guinea pig trachea model of bronchodilation. These results suggest that (R)-18c is a potential candidate for long-acting β2-AR agonists.
