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.
THE IN SITU PROTECTION OF ALDEHYDES VIA α-AMINO ALKOXIDES
Comins, Daniel L.,Brown, Jack D.
, p. 4213 - 4216 (1981)
Aromatic and aliphatic aldehydes can be protected in situ via the formation of α-amino alkoxides and their O-trimethylsilyl derivatives.
81. Loss of H2O from M + t-Butyl Complex Ions of Benzyl Alcohol in Isobutane Chemical Ionization Mass Spectrometry
Liehr, Joachim G.,Brenton, Gareth A.,Beynon, John H.,McCloskey, James A.,Blum, Wolfgang,Richter, Wilhelm J.
, p. 835 - 843 (1981)
In isobutane chemical ionization mass spectrometry benzyl alcohol exhibits ions at m/z 147 ('M +39') that arise by a loss of H2O from +, i.e. 'M + 57' complex ions.Electrophilic aromatic substitution of a proton at an ortho-position of neutral C6H5CH2OH with + and, alternatively, nucleophilic substitution of H2O at the benzylic carbon in C6H5CH2O+H2 with CH2=C(CH3)2 are discussed as possible pathways.Evidence in favor of the latter is derived from the analysis of C6D5CH2OH and C6H5CD2OH for the origin of the H-atoms lost in H2O.The inferred ion structure of m/z 147 is verified by mass-analyzed ion kinetic energy (MIKE.) measurements of its collision- activated (CA.) decomposition.MIKE./CA. spectra of mass-selected m/z 147 ions, once generated by CI(i-C4H10) from benzyl alcohol and, once, from 2-methyl-4-phenyl-2-butanol match closely and, thus, reflect identical ion structures.With reference to the simple genesis of this ion from the latter precursor, the structure in question can be concluded to be C6H5CH2CH2C+(CH3)2.
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.
2-Naphthylmethoxymethyl as a Mildly Introducible and Oxidatively Removable Benzyloxymethyl-Type Protecting Group
Sato, Takuya,Oishi, Tohru,Torikai, Kohei
, p. 3110 - 3113 (2015)
2-Naphthylmethoxymethyl (NAPOM) was developed for the protection of various hydroxy (including phenolic hydroxy and carboxy) and mercapto groups. The NAPOM group can be introduced in extremely mild conditions (naphthylmethoxymethyl chloride, 2,6-lutidine, room temperature) without concomitant acyl migration in a 1,2-diol system. Furthermore, selective removal of NAPOM in the presence of naphthylmethyl (NAP) and p-methoxybenzyl (PMB) groups and, conversely, that of PMB in the presence of NAPOM were realized. These results, as well as its easy handling and compatibility with various solvents, show that NAPOM is a novel and useful choice as a protecting group.
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.
A mild and feasible deprotection of alcohol tetrahydropyranyl or methoxymethyl ethers catalyzed by Sc(OTf)3
Oriyama,Watahiki,Kobayashi,Hirano,Suzuki
, p. 2305 - 2311 (2001)
Tetrahydropyranyl or methoxymethyl ethers can be easily deprotected by treatment of a catalytic amount of scandium trifluoromethanesulfonate along with methanol or 1,3-propanediol, respectively, to afford the corresponding parent alcohols in high to excellent yields.
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.
Reaction of methylcerium reagent with tertiary amides: Synthesis of saturated and unsaturated ketones from tertiary amides
Kurosu, Michio,Kishi, Yoshito
, p. 4793 - 4796 (1998)
The reaction of CeCl3-MeLi to tertiary amides has been studied. The reagent prepared from cerium(III) chloride and methyllithium at 0°C adds cleanly to morpholine amides to give the corresponding methyl ketones. Even in the presence of a large excess of the reagent, no tertiary alcohol formation is observed, indicating that the tetrahedral intermediates are stable under the reaction conditions employed.
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).
