Bis- -tert.-butyl

Peroxy ketals Butyl 4,4-bis (tert-butyl peroxy) valerate 143 160... 

Substitution of the dimethylsilyl group by bis(tert-butyl)-stannyl does not change the structure in solution, e.g. 33 is found to be monomeric. A very interesting dimer is 26. In contrast to the centrosymmetrical dimer of 1 (C-Symmetry), 26 has a twofold axis (C2, see Fig. 9). This special structure may be due to intramolecular Lewis acid-base interactions between the boron and nitrogen atoms 39). Nevertheless,... 

Functionalized silacyclobutanes 16 result from photochemical decomposition of [azido-, isocya-nato- and isothiocyanato-bis(tert-butyl)silyl]diazoacetates 15. They undergo a remarkably facile ring-expansion reaction to cyclic O-silyl ketene acetals 17 even at 60°C. 

The problem of diastereoselectivity in additions to cyclic radicals arising from the opening of bi- or tricyclic epoxides, e. g. cycloheptene oxide or norbornene oxide, has been addressed only recently [32], In the former case, reasonable selectivities can be obtained with titanocene dichloride (trans cis = 76 24), but excellent selectivities are observed with bis(tert-butyl)titanocene dichloride (transxis = 94 6), as shown in Scheme 12.17. 

The sterically hindered base 2,6-bis(tert-butyl)pyridine does not inhibit cyclization triaryl-amine retards this reaction photosensibilized one-electron oxidation of a diene leads to the same products, which are formed in the presence of ammoniumyl salt. As shown, in majority of cases, only the cation-radical chain mechanism of the diene-diene cyclization is feasible (Bauld et al. 1987). Meanwhile, cyclodimerizations of 2,4-dimethylpenta-l,3-diene (Gassman and Singleton 1984) and l,4-dimethylcyclohexa-l,3- or -1,4-diene (Davies et al. 1985) proceed through both mechanisms. 

Synonyms Bis(tert-butyl)chromate acid, di-tert-butyl ester... 

BAIN2O4C58H74, Aluminum, dimethanol-1,2-bis(2-hydroxy-3,5-bis(tert-butyl)benzylide-neimino)ethane-, tetraphenylborate, 34 17... 

NO6VC14H20, Vanadate(l-), hexacarbonyl-, tetraethylammonium, 34 98 NRh4C2iH35-H20, Rhodium(lll), tricyano(pen-tamethylcyclopentadienyl)-, tetraethylammonium, monohydrate, 34 167 N2AIBO4C58H74, Aluminum, dimethanol-1,2-bis(2-hydroxy-3,5-bis(tert-butyl)benzyhde-neimino)ethane-, tetraphenylborate,... 

The X-ray crystal structure determination of ferf-butylzinc bis(tert-butyl) arsenide (242) revealed a similar structural feature as observed in 240 and 241, i.e. a flat Zn—As—Zn—As central four-membered ring as a resnlt of -bridging arsenide groups and trigonal planar zinc atoms. ... 

Hexanoate Methyl 5-<5-J 2-( 3.5-Bis-[tert.-butyl-dimethyl-silyloxyl-2-methylen-cyclohexyliden)-ethyliden J-1 -methyl-bicyclo [4.3.0]non-9-yl>-2,2-difluoro-F.lOb, 184 (CO - CFj)... 

Compound 45 was also obtained by a second route. We prepared the bis (tert-butyl ester) ( )-42 by transforming the DB18C6 diol 40 into bis-malonate 41,... 

Bis tert.-butyl]-1,4-thiatellurin 1,1-dioxide (m.p. 146°) was similarly prepared in 80% yield3. 

Cyclopropenimin Bis-[tert.-butyl-thio]-N-cyan- E17d, 3011 (SR - =N —CN)... 

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