Ring-closure reactions. 8. Synthesis and ultraviolet spectra of macrocyclic aromatic ethers

Mandolini, Luigi; Masci, Bernardo

doi:10.1021/jo00437a012

Cited by 8 publications

(7 citation statements)

References 4 publications

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“…Preparation and purification of 2-(3-bromopropyloxy)phenol (PhBr7), 2-(12-bromododecyloxy)phenol (PhBr16), 1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (1), and (2S,3S)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butanedibromide(2)havebeendescribed. 8a, [12][13][14] Kinetics. Reactions were followed in deionized, distilled, CO2free water as described.…”

Section: Methodsmentioning

confidence: 99%

“…The identification was made by comparison with an authentic sample. 12 NMR. 1 H NMR measurements were carried out on a Bruker AC300P instrument operating at 300.13 MHz.…”

Section: Methodsmentioning

confidence: 99%

“…Materials. Preparation and purification of 2-(3-bromopropyloxy)phenol (PhBr7), 2-(12-bromododecyloxy)phenol (PhBr16), 1,4-bis( N -hexadecyl- N , N -dimethylammonium)butane dibromide ( 1 ), and ( 2S , 3S )-2,3-dimethoxy-1,4-bis( N -hexadecyl- N , N -dimethylammonium)butane dibromide ( 2 ) have been described. 8a,− …”

Section: Methodsmentioning

confidence: 99%

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Cyclizations of 2-(ω-Bromoalkyloxy)phenoxide Ions in Dicationic Surfactants

et al. 1999

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Cyclization of 2-(3-bromopropyloxy)phenoxide ion (PhBr7) in micelles is a model for SN2 reactions of nucleophilic anions at micelle-water interfaces. In this paper we report observed rate constants (kobs) in aqueous micelles of dimeric surfactants. kobs in 1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide ( 1) is constant in a range of concentration, then increases at high [1], suggesting a transition to a different type of aggregate. A 1 H NMR investigation confirms a phase transition at the [1] which corresponds to the reactivity change. (2S,3S)-2,3-Dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (2) forms very large aggregates and shows a modest catalytic effect. Cyclization of 2-(12-bromododecyloxy)phenoxide ion (PhBr16) in 1 under preparative conditions yields the intramolecular cyclic product only despite a low effective molarity and a relative high substrate concentration. This result reveals the presence of a well-organized substrate-surfactant aggregate.

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Section: Methodsmentioning

confidence: 99%

“…The identification was made by comparison with an authentic sample. 12 NMR. 1 H NMR measurements were carried out on a Bruker AC300P instrument operating at 300.13 MHz.…”

Section: Methodsmentioning

confidence: 99%

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Cyclizations of 2-(ω-Bromoalkyloxy)phenoxide Ions in Dicationic Surfactants

et al. 1999

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“…Interestingly, 5MR shows a bathochromic shift that is ≈20 nm larger than those of indeno‐NP, 6MR, and 7MR. It has been reported that the five‐membered alkylenedioxy moiety exhibits extended conjugation over the five‐membered ring owing to hyperconjugation between the σ‐orbital of the alkylene group and the π‐orbital of the oxygen atom . Actually, the HOMO of 5MR as estimated by DFT calculations delocalizes over the whole five‐membered ring of the alkylenedioxy moiety, and the σ‐orbital of the alkylene group contributes to the π‐conjugation (Figure S130, Supporting Information).…”

Section: Methodsmentioning

confidence: 98%

“…In this study, we designed novel naphthopyran derivatives possessing alkylenedioxy moieties as a means to control the thermal fading speed of the TC form and reduce the generation of the long‐lived TT form. The reactivity and optical properties of the 1,2‐alkylenedioxy benzene significantly depend on the ring‐size of the alkylenedioxy moiety owing to changes in electron‐donating ability and π‐conjugation length upon changing the conformation of the ring . We introduced alkylenedioxy moieties to the 9‐ and 10‐positions of 3 H ‐naphthopyran (3HNP) and investigated the effects of ring size on the photochromic properties of the resultant molecules.…”

Section: Methodsmentioning

confidence: 99%

On‐Demand Control of the Photochromic Properties of Naphthopyrans

et al. 2018

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minutes/hours to completely return to the CF. The residual color imparted by the TT form and the slow thermal back-reaction of the TC form are considered as problems to be solved. [9][10][11][12][13] The thermal backreaction speed of colored naphthopyrans can be modulated by the introduction of an electron-donating group at the para position of the 3-phenyl ring. [4] However, substitution at the 3-phenyl ring typically causes significant changes in the color of the colored species. Although the speed of the thermal back-reaction can be modulated by exploiting steric effects to destabilize the TC form and the long-lived TT form, the synthetic procedures required to yield the desired products are not simple and moderate control of the thermal backreaction speed for photochromic lenses is difficult to achieve. [14][15][16][17][18][19] In order to design appropriate naphthopyran derivatives showing on-demand photochromic properties, the independent control of the thermal back-reaction speed is an important challenge in the development of advanced photochromic materials. Within this context, we herein present a molecular design strategy that can be used to modulate the thermal fading speed without significant changes to other photochromic properties.In this study, we designed novel naphthopyran derivatives possessing alkylenedioxy moieties as a means to control the thermal fading speed of the TC form and reduce the generation of the long-lived TT form. The reactivity and optical properties of the 1,2-alkylenedioxy benzene significantly depend on the ring-size of the alkylenedioxy moiety owing to changes in electron-donating ability and π-conjugation length upon changing the conformation of the ring. [20][21][22] We introduced alkylenedioxy moieties to the 9-and 10-positions of 3H-naphthopyran (3HNP) and investigated the effects of ring size on the photochromic properties of the resultant molecules. Remarkably, the thermal back-reaction speed of the newly designed naphthopyran derivatives was found to be controllable independently of other photochromic properties, such as the color of the colored species, by changing the alkyl chain length of the alkylenedioxy moiety. In addition, intramolecular hydrogen bonding is very important for modulating the conformation and stability of the structural isomers. [23,24] The undesirable residual color attributable to the formation of the TT form upon cessation of light irradiation is effectively reduced owing to the hydrogen bonding between the oxygen atom at the 10-position and the olefinic proton at the 1-position in the TC form, resulting in fast photoswitchable Photofunctional compounds have emerged as critically important materials for both fundamental studies and industrial applications. Control of the thermal decoloration speed to within several seconds while sustaining satisfactory photochromic colorability is an important challenge for the application of such materials to photochromic lenses and smart windows. Photochromic naphthopyran derivatives are utilized for photoch...

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