- Medium-sized cyclophanes. Part 62:1 formylation of anti-[n.2]metacyclophanes - Through-space electronic interactions between two benzene rings
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Formylation of anti-[n.2]metacyclophanes (1) (n = 2, 3, 4) with dichloromethyl methyl ether in the presence of TiCl4 occurred selectively at para-position to the internal methyl substituents of anti-[n.2]metacyclophanes. Similar reaction of anti-5,13-di-tert-butyl-8,16-dimethyl[2.2]metacyclophane (6a) with dichloromethyl methyl ether in the presence of TiCl4 led to ipso-formylation at the tert-butyl group to give anti-5-tert-butyl- 13-formyl-8,16-dimethyl[2.2]-metacyclophane (7a) as well as the corresponding 2,7-di-tert-butyl-trans-10b, 10c-dimethyl-10b,10c-dihydropyrene (10), anti-5-tert-butyl-8,16-dimethyl-13-(3-methyl-1-butene-2-yl)[2.2] metacyclophane (8), and anti-5,13-di-tert-butyl-exo-1-hydroxy-8,16-dimethyl[2.2]metacyclophane (9) depending on the reaction conditions. The higher yield of ipso-formylated product is obtained in the presence of AlCl3 MeNO2 in 80% yield along with anti-5-tert-butyl-8,16-dimethyl-13- (3-methyl-1-butene-2-yl)[2.2]metacyclophane (13). Thus, the yield of ipso-formylation at the tert-butyl group of 6a was strongly affected by the activity of the formylation catalyst. Interestingly, in the formylation of anti-6,14-di-tert-butyl-9,17-dimethyl[3.2]metacyclophane (6b) under the same reaction conditions, syn-6,14-di-tert-butyl-7-formyl-9,17-dimethyl[3.2]metacyclophane (14b) was obtained in 40% yield arising from the anti-syn-ring inversion of the formylation intermediate along with ipso-formylation product 7b in 42% yield. In the formylation of anti-[4.2]metacyclophane (6c) only the mono-ipso-formylated product 7c was obtained in 92% yield. The formation of a two-fold ipso-formation product, i.e., anti-5,13-diformyl-8,16-dimethyl[2.2]metacyclophane (3a), was not observed under the reaction conditions used. The mechanism of the ipso-formation as well as the formation of the present novel reaction products 8 and 9 is also discussed.
- Yamato, Takehiko,Furukawa, Tsuyoshi,Tanaka, Kan,Ishi-i, Tsutomu,Tashiro, Masashi
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- A convenient synthesis of tri- and tetramethylbenzaldehydes from readily available phenols
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This letter describes a convenient synthesis of the six isomeric tri- and tetramethylbenzaldehydes, which are not readily available from major chemical suppliers. Formylation of readily available phenols via electrophilic aromatic substitution provides compounds containing the correct aromatic substitution pattern. ?Suzuki cross-coupling of the corresponding trifluoromethanesulfonates with methylboronic acid then provides the benzaldehydes as single isomers. Georg Thieme Verlag Stuttgart. New York.
- Dhankher, Persis,Sheppard, Tom D.
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supporting information
p. 381 - 384
(2014/03/21)
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- Isosteric analogs of lenalidomide and pomalidomide: Synthesis and biological activity
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A series of analogs of the immunomodulary drugs lenalidomide (1) and pomalidomide (2), in which the amino group is replaced with various isosteres, was prepared and assayed for immunomodulatory activity and activity against cancer cell lines. The 4-methyl and 4-chloro analogs 4 and 15, respectively, displayed potent inhibition of tumor necrosis factor-α (TNF-α) in LPS-stimulated hPBMC, potent stimulation of IL-2 in a human T cell co-stimulation assay, and anti-proliferative activity against the Namalwa lymphoma cell line. Both of these analogs displayed oral bioavailability in rat.
- Ruchelman, Alexander L.,Man, Hon-Wah,Zhang, Weihong,Chen, Roger,Capone, Lori,Kang, Jian,Parton, Anastasia,Corral, Laura,Schafer, Peter H.,Babusis, Darius,Moghaddam, Mehran F.,Tang, Yang,Shirley, Michael A.,Muller, George W.
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p. 360 - 365
(2013/02/23)
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- Method of producing dialkyl- and trialkyl-substituted benzaldehydes
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This invention relates to a process for preparing specific substituted benzaldehydes through the reaction of substituted benzenes with carbon monoxide and aluminum chloride at a relatively low pressure, at a low temperature, and in the presence of at most
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- Aryl-substituted cycloalkanes and cycloalkenes and herbicidal use thereof
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Disclosed are herbicidal aryl substituted cycloalkyl and aryl substituted cycloalkenyl compounds, herbicidal compositions, and herbicidal use of the compounds and compositions. The aryl substituent is selected from substituted phenyl, unsubstituted or substituted five-membered heterocycle, and unsubstituted or substituted six-membered heterocycle.
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- Dual Reactivity of the Formyl Cation as an Electrophile and a Broensted Acid in Superacids
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The nature of the formyl cation in the Gattermann-Koch formylation was studied by comparing the formylation with the acetylation and sulfonation in CF3SO3H-SbF5 and FSO3H-SbF5, respectively.The results of the kinetic studies in CF3SO3H-SbF5 showed that the formyl cation has dual reactivity as an electrophile and as a Broensted acid.Upon comparing the formylation with the sulfonation in FSO3H-SbF5, it was found that the protonated aromatic compounds also act as Broensted acids to produce formyl cations.Therefore, the formylation has a priority over other typical electrophilic substitutions under conditions where most of aromatic compounds are protonated because the formyl cation is reproduced close to the aromatic compounds by the protonation of CO with not only superacids but also protonated aromatic compounds.
- Tanaka, Mutsuo,Fujiwara, Masahiro,Ando, Hisanori
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p. 3846 - 3850
(2007/10/02)
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