Insights to the subtle reactivity patterns of hydroxy-substituted carbazoles allows the precise synthesis of unsymmetrical azatrioxa[8]circulenes by the reaction of N-benzyl-2,7-di-tert-butyl-3,6-dihydroxycarbazole with two different 1,4-benzoquinones in the presence of an oxidant (chloranil) and a Lewis acid (BF3OEt2). The unique synthetic control obtained originates from the selectivity obtai...

Metal b-tetrakis(tert-butyl)phthalocyanines are the most commonly used phthalocyanines due to their high solubility, stability, and accessibility. They are commonly used as a mixture of four regioisomers, which arise due to the tert-butyl substituent on the b-position, and to the best of our knowledge, their regioselective synthesis has yet to be reported. Herein, the C4hselective synthesis of ...

The title compound, C(14)H(30)N(2)O(2)S(2), is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R)-N-tert-butanesulfinyl]ethanediimine. There are two almost identical mol-ecules in the asymmetric unit, the mol-ecular conformation of which is stabilized by an intra-molecular N-H⋯N hydrogen bond.

1. The major metabolites of 3,5-di-tert.-butyl-4-hydroxytoluene (BHT) in the rat are 3,5-di-tert.-butyl-4-hydroxybenzoic acid (BHT-acid), both free (9% of the dose) and as a glucuronide (15%), and S-(3,5-di-tert.-butyl-4-hydroxybenzyl)-N-acetylcysteine. 2. The mercapturic acid does not appear to derive from the usually accepted enzyme mechanism, and may involve a non-enzymic reaction between BH...

(2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline were synthesized (as Fmoc-, Boc-, and free amino acids) in 2-5 steps. The key step of each synthesis was a Mitsunobu reaction with perfluoro-tert-butanol, which incorporated a perfluoro-tert-butyl group, with nine chemically equivalent fluorines. Both amino acids were incorporated in model α-helical and polyproline helix peptides. Each ...

The simple dialkyl oxalates are generally liquids at room temperature except for dimethyl and di-tert-butyl oxalate which melt at 327 and 343 K. The crystal structures of diethyl, di-iso-propyl, di-n-butyl, di-tert-butyl and methyl ethyl oxalates were determined. The liquid esters were crystallized using the cryocrystallization technique. A comparison of the intermolecular interactions and pack...

The motional restrictions of the proline pyrrolidine ring allow this secondary amine amino acid to act as a turn inducer in many peptides and proteins. The pyrrolidine ring is known to exhibit two predominant pucker modes (i.e., C-4 (Cgamma) exo and endo envelope conformers whose ratio can be controlled by proper substituents in the ring). In nature, the exo puckered 4(R)-hydroxy-l-proline play...

Susceptibility to metabolism is a common issue with the tert-butyl group on compounds of medicinal interest. We demonstrate an approach of removing all the fully sp(3) C-Hs from a tert-butyl group: replacing some C-Hs with C-Fs and increasing the s-character of the remaining C-Hs. This approach gave a trifluoromethylcyclopropyl group, which increased metabolic stability. Trifluoromethylcyclopro...

methyl tert-butyl ether (mtbe), a gasoline octane enhancer, was introduced as a substitute for lead tetraethyl over 30 years ago. widespread use of mtbe in gasoline, has introduced mtbe into the environment compartments, mostly into the under ground and surface water and water as a second most frequently detected contaminant. in this study, we have isolated pure cultures from bacterial consorti...

The title compound, 2-{2-[1,3-di-tert-butyl-4-(tert-butyl-amino)-2-(tert-butyl-imino)-1,3,2λ(5),4-diaza-diphosphetidin-2-yl]-1-(4-meth-oxy-phen-yl)prop-2-en-1-yl}-5,5-dimethyl-1,3,2λ(5)-dioxaphosphinan-2-one, C(31)H(57)N(4)O(4)P(3), was synthesized from the Phospha-Michael addition reaction of cyclo-diphos-pha-zane [(t-BuNH)P(μ-Nt-Bu)](2) and allenyl-phospho-nate [(OCH(2)C(CH(3))(2)CH(2)O)P(O)C...