Medium-Sized Cyclophanes. 43.1First Evidence foranti−syn-Ring Inversion under the Nitration of 5,13-Di-tert-butyl-8,16-dimethoxy[2.2]metacyclophane

1997 ◽  
Vol 62 (22) ◽  
pp. 7560-7564 ◽  
Author(s):  
Takehiko Yamato ◽  
Hideo Kamimura ◽  
Tsuyoshi Furukawa
Keyword(s):  
Ring Inversion ◽  
Tert Butyl

Medium-sized cyclophanes. Part 62:1 Formylation of anti-[n.2]metacyclophanes — Through-space electronic interactions between two benzene rings

2003 ◽  
Vol 81 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Takehiko Yamato ◽  
Tsuyoshi Furukawa ◽  
Kan Tanaka ◽  
Tsutomu Ishi-i ◽  
Masashi Tashiro
Keyword(s):  
Methyl Ether ◽  
Electrophilic Aromatic Substitution ◽  
Similar Reaction ◽  
Reaction Conditions ◽  
Ring Inversion ◽  
Electronic Interactions ◽  
Strained Molecules ◽  
Tert Butyl ◽  
Butyl Group ◽  
Tert Butyl Group

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]-meta cyclophane (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] meta cyclophane (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. Key words: cyclophanes, strained molecules, electrophilic aromatic substitution, ipso-formylation, σ-complex intermediates, through-space electronic interactions.

A mechanism of mitochondrial damage induced by tert-butyl hydroperoxide and microsomes in vitro

1990 ◽  
Vol 80 (2) ◽  
pp. 226-232
Author(s):  
Tomoaki Matsuo ◽  
Yumiko Kashiwaki ◽  
Saburo Itoo
Keyword(s):  
Mitochondrial Damage ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide

Crystal structure of p-bis(tert-butyl-trimethylsiloxyl-methyliden-phosphino)-benzene,(C4H9C((CH3)3SiO)P)2C6H4

1995 ◽  
Vol 210 (3) ◽  
pp. 224-224 ◽  
Author(s):  
F. Knoch ◽  
R. Appel ◽  
H. Wenzel
Keyword(s):  
Crystal Structure ◽  
Tert Butyl

Crystal structure of 5-tert-butyl-3-ethinyl-2,2-dimethyl-1-(2-trimethylsilyl-ethinyl)-cyclohexane-1,3-diol, C19H32O2Si

1996 ◽  
Vol 211 (12) ◽  
Author(s):  
K. Peters ◽  
E.-M. Peters ◽  
J. Fischer ◽  
R. Brückner
Keyword(s):  
Crystal Structure ◽  
Tert Butyl

METHYL TERT- BUTYL ETHER OCCURRENCE AND DEGRADATION IN WATER

2007 ◽  
Vol 6 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Ilie Siminiceanu
Keyword(s):  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Tert Butyl
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