Bis -r-butyl

The sterically demanding secondary alcohol bis(r-butyl)methanol (2,2,4,4-tetramethylpentan-3-ol) does not react with Cr N(SiMe3)2 3 or Cr(NEt2)4, but the chromium(III) complexes Cr(OCHBu2)3 THF and LiCr(OCHBu2)4, and the chromium(IV) complex Cr(OCHBu2)4 have... 

Diaziridinones react with bifunctional carbanions by ring enlargement to give pyrazolinones <1992JOC7359> thus diaziridinone 94 with malononitrile affords l,2-bis-/ r/-butyl-3-aminopyrazolin-5-one 95 (Scheme 52). 

Related Reagents. (/ )- ,l -Bi-2,2 -naphthotitanium Dichloride (/ )- ,T-Bi-2,2 -naphthotitanium Diisopropoxide Dihydroquinine Acetate (15,9.S)-l,9-Bis [(r-butyl)dimethylsilyloxy]-methyl -5-cyanosemicorr in 2,2-Dimethyl-a,a,a, a -tetraphenyl-1,3-dioxolane-4,5-dimethanolatotitanium Diiso-... 

A similar approach converted enantiomerically pure (2R,3R)-2,3-isopropylidenedioxy-cyclopent-4-en-l-one derived from cyclopentadiene [209] into (—)-l-deoxymannonojirimycin and (-)-l-deoxytalonojirimycin (l,5-dideoxy-l,5-imino-D-talitol) [210]. Enone 462 was converted to (2R,35 )-2,3-bis ( r -butyl)dimethylsilyloxy]cyclopent-4-en-l-one and then to (-f)-1 -deoxynojirimycin [211]. 

Besides toluenes, ethyl- or isopropyl-substituted arenes can also be oxidized selectively to acetyl-substituted systems which may be transformed further into the corresponding carboxylic acids. Even f-butyl groups, as in 4,4 -bis(r-butyl)biphe-nyl, can be oxidized to the corresponding carboxyl groups [7], Due to the strong interest in the commercial production of 2,6- and 1,4-dicarboxynaphthalenes, there are many patents concerning the oxidation of methyl-, ethyl-, or isopropyl-substituted arenes to the aromatic di-acids [8], Also, toluenes or xylenes connected by spacer groups like -0-, -S-, isopropyl or hexafluoroisopropyl are of practical interest for applications in air oxidation reactions (see Section 2.4.5.2.V). 

According to Eqs. (75) and (76), tetraphenyldiphosphane is formed in quantitative amounts from Ph2PCl in CH2C12 at — 30°C. The yield is slightly less for tetramesityldiphosphane formed from Mes2PCl. Bis(r-butyl)chlorophosphane, on the other hand, does not react with BSD. 

H-Azepine, 3,5-bis( r-butyl)-1 -ethoxycarbonyl-photoaddition reactions, with oxygen, 7, 523... 

Oxidation of alcohols. Trimethylsilyl ethers of secondary alcohols are oxidized in CH2CI2 to ketones in 95-1007o yield by trityl tetrafluoroborate. Oxidation of ethers of primary alcohols is too slow to be useful. Consequently selective oxidation of ethers of secondary alcohols is possible. Oxidation of bissilyl ethers is not clean, but use of bistrityl ethers or bis-r-butyl ethers is a useful method. The latter ethers are useful for selective oxidation of some 1,3-diols, because only... 

Initiator decomposition ( Vy) Dibenzoyl peroxide Dibenzoyl peroxide Azobisisobutyronitrile Bis(/-butyl) peroxide Bis(r-butyl) peroxide Bis(r-butyl) peroxide Bis(/-butyl) peroxide... 

The only stable Pd(II) compound with bis(/ r/-butyl)acetylene may be prepared by reaction of Bu CCBu with bis(benzonitrile)dichloropalladium(II) or di-/x-chloro-dichlorodi (ethylene )dipalladium (II) ... 

Alternate Names l,l -(l-propene-l,3-diyl)bis[l,l,l-trimethy-Isilane] (lE)-l-propene-l,3-diylbis[trimethylsilane] (E)-prop- 1-ene-1,3-diylbis(trimethylsilane) (IZ)- 1-propene-1,3-diylbis[trimethylsilane], CAS 141291-16-9 Bis(r-butyl-dimethylsilyl) derivative (l )-l-propene-l,3-diylbis[(l,l-dimethylethyl)dimethylsilane] Bis(dimethylphenyl) derivative [[(l )-3-dimethylphenylsilyl)-1-propen-l-yl]dimethyl-silyl]-benzene other derivatives are known but less widely used. 

Ohnishi (Sakamoto etal., 1991) has described an oligomeric derivative of prostaglandin Bi (PGB2) and ascorbic acid. In a rat bilateral carotid occlusion-reperfiision injury complicated by haemorrhagic hypotension, this compound reduced a-phenyl-r-butyl nitrone (PBN) spin-trapped radicals and thiobarbituric acid-reactive products (TBARs) (a measure of lipid peroxidation) in isolated... 

The structure of this silaamidide salt consists of well-separated, noninteracting lithium cations [Li(12-crown-4)THF]e and N,N -bis(2,4,6-tri-/-bu-tylphenyl)-f-butylsilaamidide anions. In the anion, the silicon is tricoordi-nated to a carbon atom of the r-butyl group and to two nitrogen atoms. 

SnCLu Ti(OPr )2Cl2, and methyl acetylenedicarboxylate (MAD) (bis(2,6-/< r/-butyl-4-methylphenoxy)-methyl-aluminum) are most often used as LA. Meanwhile, nonconventional procedures, for example, the reaction in water (102 and references therein), can be used to perform cycloadditions of nitroalkenes. 

Direct phase-transfer catalysed epoxidation of electron-deficient alkenes, such as chalcones, cycloalk-2-enones and benzoquinones with hydrogen peroxide or r-butyl peroxide under basic conditions (Section 10.7) has been extended by the use of quininium and quinidinium catalysts to produce optically active oxiranes [1 — 16] the alkaloid bases are less efficient than their salts as catalysts [e.g. 8]. In addition to N-benzylquininium chloride, the binaphthyl ephedrinium salt (16 in Scheme 12.5) and the bis-cinchonidinium system (Scheme 12.12) have been used [12, 17]. Generally, the more rigid quininium systems are more effective than the ephedrinium salts. 

Ci6H36N4Te2, Tellurium, bis(/r-tert-butyl-imido)bis(tert-butylimido-), 34 45 C18H14RU, Ruthenium, bis(T) -indenyl)-, 34 64 C18H15ASF2, Arsenic(V), difluorotriphenyl-, 34 34... 

O4AICIN2C34H54, Aluminum, dimethanol-1,2-bis(2-hydroxy-3,5-bis(tert-butyl)benzylide-neimino)ethane-, chloride, 34 17 O4BM0N6C16H17, Molybdenum(II), dicarbonyl hydridotris( 1 -py razolyl)borato 7)-(1,2,3)-(+)-( 1 R,2R)-1 -(methoxycarbonyl)-2-propen-l-yl -, 34 105 O4B2C12H4, Diborane(4), catechol derivative, 34 4... 

The radical anion of /3-trimethylsilylstyrene also undergoes dimerization but coupling takes place at the carbons a to silicon 33). The kinetics of the alkyne dimerization, followed by ESR, showed the reaction to be second order in radical anion 43). With Li+, Na+, K+, or Rb+ as the counterions, the rate increases in the order Si < C < Ge 45). Consistent with the increased stability of the trimethylsilyl-substituted radical anion, the radical anion of 1,4-bis(trimethylsilyl)butadiyne, produced by reduction with Li, Na, K, Rb, or Cs in THF is stable at room temperature even on exposure to air, whereas the carbon analog, 1,4-di-r-butyl-1,3-butadiyne radical anion, dimerizes by second-order kinetics at -40° (42). The enhanced stability of the trimethylsilylalkynyl radical anions has been attributed to p-drr interactions (42). 

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