Studies on selective preparation of aromatic compounds. 15. The Lewis acid catalyzed transalkylation of some tert-butyldiphenylmethanes and -ethanes in aromatic solvents

Tashiro, Masashi; Yamato, Takehiko; Fukata, Gouki

doi:10.1021/jo00401a027

Cited by 40 publications

(13 citation statements)

References 5 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,ethane (1a) has been prepared according our previous paper (12). The cross coupling reactions (13) of 4-methoxyphenylmagnesium bromide with 1,3dibromopropane and 1,4-dibromobutane have been carried out in the presence of cuprous bromide as a catalyst in a mixture of hexamethylphosphoric triamide (HMPA) and tetrahydrofuran at reflux temperature to give the desired 1,3bis (4-methoxyphenyl)propane (1b) and 1,4-bis(4-methoxyphenyl)butane (1c) in satisfactory yields.…”

Section: Introductionmentioning

confidence: 64%

“…using the C(3), C(7), C (12), and C(16) and C(3), C(7), C(13), and C(17) carbons as roots, respectively, to avoid πelectronic repulsion as shown in the side view of the ORTEP drawing. Although the double bond lengths between C(1)-C(2) in the syn-3b and syn-3c are reasonable, 1.332 and 1.354 Å, respectively, these compounds have quite different conformations of the two aromatic rings due to the different methylene chain length.…”

Section: Resultsmentioning

confidence: 99%

“…The C(4), C(7), C (12), and C(15) carbons are out of the C(3)-C(5)-C(6)-C (8) and C(13)-C(14)-C(16)-C(17) planes. The dihedral angles of the C(3)-C(5)-C(6)-C (8) plane between the C(3)-C(4)-C(5) and C(6)-C(7)-C(8) planes, and those of the C(13)-C(14)-C(16)-C(17) plane between the C(14)-C(15)-C(16) and C(12)-C(13)-C(17) planes are 1.77°, 4.52°, 1.53°, and 5.54°, respectively, showing that the aromatic rings in the syn-3b adopts unsymmetrically strained structure and the rigid ethylene chain against the flexible methylene chains might loose the strain.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Yamato¹,

Fujita²,

Futatsuki³

et al. 2000

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

A series of [n.2]metacyclophanenes (3) and (6) were prepared in good yields by a McMurry cyclization of 1,n-bis(3-acetyl-4-methoxyphenyl)alkanes (2) and 1,3-bis(3-formyl-4-methoxyphenyl)propane (5), respectively. Compounds 3b, 3c exist in the syn-conformation due to the steric repulsion between the methyl groups at the ethano bridge and the methoxy groups at the aromatic rings while compound 6 prefers the anti-conformation typical of [3.2]metacyclophanes. The assignment of syn-conformations has been confirmed by 1 H NMR analyses and X-ray diffraction studies. Photoinduced transannular cyclization of [n.2]metacyclophanenes (3) and (6) in the presence of iodine as an oxidant afforded phenanthrene-anellated polycyclic aromatic hydrocarbons. Apparently, the rate of the photocyclization of anti-6 was found to be much faster than that of syn-3b and almost completed within 1 h. Thus, the different reactivities for the irradiation of syn-and anti-conformer were observed. The reason for the present preference for the formation of trans-dihydrophenanthrene rather than cis-dihydrophenanthrene as the intermediate might be attributable to the more stable chair form transition state than boat one and the conformational fixation to the chair form in the ground and transition state is possible in the anti-conformer.Résumé : Faisant appel à une réaction de cyclisation de McMurry des 1,n-bis(3-acétyl-4-méthoxyphényl)alcanes (2) et 1,3-bis(3-formyl-4-méthoxyphényl)propane (5) respectivement, on a préparé une série de [n,2]métacyclophanènes (3) et (6). Les composés 3b et 3c existent dans la conformation syn en raison de la répulsion stérique entre les groupes méthyles du pont éthano et les groupes méthoxy des noyaux aromatiques alors que le composé 6 adopte la conformation anti des [3,2]métacyclophanes. L'attribution des conformations syn a été confirmée par des analyses de RMN du 1 H et des études de diffraction des rayons X. La cyclisation transannulaire photoinduite des [n,2]métacyclophanènes (3) et (6) en présence d'iode, utilisé comme antioxydant, conduit à des hydrocarbures aromatiques polycycliques du type phénanthrène avec annellation. Apparemment, la vitesse de photocyclisation du produit anti-6 est beaucoup plus rapide que celle du syn-3b et elle est pratiquement complète en une heure. Ainsi, on a pu observer des réactivités différentes pour l'irradiation des conformères syn et anti. La raison de la formation observée d'une préférence pour la formation comme intermédiaire du trans-dihydrophénanthrène plutôt que du cis-dihydrophénanthrène pourrait être attribuée à l'état de transition en forme chaise qui est plus stable que celui en forme bateau ainsi que le fait que la conformation des états tant fondamental que de transition du conformère anti peut être fixée à la forme chaise.

show abstract

Section: Introductionmentioning

confidence: 64%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Yamato¹,

Fujita²,

Futatsuki³

et al. 2000

Can. J. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The starting compound 1,2-bis(5-t-butyl-2-methylphenyl) ethane 1 18 has been prepared according our previous paper by using the t-butyl group as a positional protective group on the aromatic ring. 16 Although the TiCl 4 -catalysed formylation of compound 1 with dichloromethyl methyl ether 19 at 20°C for 2 h led to complete two-fold formylation, a mixture of the desired 1,2-bis(5-t-butyl-3-formyl-2-methylphenyl)ethane 2 and other isomers was obtained.…”

Section: Resultsmentioning

confidence: 99%

Medium-Sized Cyclophanes, 63.¹ Synthesis and Structure of [2.2]Metacyclophane-1,2-Diol and Conversion Into [2.2]Metacyclophane-1,2-Dione by Swern Oxidation

Yamato

Hironaka

Saisyo

et al. 2003

Journal of Chemical Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…This reflects the response of the C Ar -CMe 3 bond distances to the steric interactions between the bulky substituents and the aromatic ring. Interestingly, a previous report shows that tert-butyl groups in the ortho positions of phenols can be easily removed through an acid-catalysed retro-Friedel-Crafts alkylation reaction (Tashiro et al, 1978), a process which relieves this steric strain. Fig.…”

Section: Figurementioning

confidence: 99%

The antioxidant methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Wang

Chen

et al. 2014

Acta Crystallogr C

View full text Add to dashboard Cite

The title compound, C18H28O3, was prepared by the reaction of 2,6-di-tert-butylphenol with methyl acrylate under basic conditions using dimethyl sulfoxide as the promoter. The structure of this antioxidant indicates significant strain between the ortho tert-butyl substituents and the phenolic OH group. In spite of the steric crowding of the OH group, it participates in intermolecular hydrogen bonding with the ester carbonyl O atom.

show abstract

Studies on selective preparation of aromatic compounds. 15. The Lewis acid catalyzed transalkylation of some tert-butyldiphenylmethanes and -ethanes in aromatic solvents

Cited by 40 publications

References 5 publications

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-Sized Cyclophanes, 63.¹ Synthesis and Structure of [2.2]Metacyclophane-1,2-Diol and Conversion Into [2.2]Metacyclophane-1,2-Dione by Swern Oxidation

The antioxidant methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Contact Info

Product

Resources

About

Studies on selective preparation of aromatic compounds. 15. The Lewis acid catalyzed transalkylation of some tert-butyldiphenylmethanes and -ethanes in aromatic solvents

Cited by 40 publications

References 5 publications

Medium-sized cyclophanes. Part 53.1 Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-sized cyclophanes. Part 53.1 Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-Sized Cyclophanes, 63.1 Synthesis and Structure of [2.2]Metacyclophane-1,2-Diol and Conversion Into [2.2]Metacyclophane-1,2-Dione by Swern Oxidation

The antioxidant methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Contact Info

Product

Resources

About

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-sized cyclophanes. Part 53.¹ Synthesis and conformational studies, and photoinduced cyclization of syn-[n.2]metacyclophanenes

Medium-Sized Cyclophanes, 63.¹ Synthesis and Structure of [2.2]Metacyclophane-1,2-Diol and Conversion Into [2.2]Metacyclophane-1,2-Dione by Swern Oxidation