4-Amino-6-tert.-butyl

Amino-tert. butyl Alcohol (2-Hydroxyiso-butylamine, aminotrimethylcarbinol)... 

Transfer of substituted aromatic groups from silicon to boron is an efficient synthetic pathway for the preparation of aryl-halogenoboranes and diarylhalogenoboranes with different aryl groups. Substitution reactions of Cbis(trimethylsilyl)amino]--tert-butyl chloroborane have been reported and the reaction of phosphonium ylides with alkyldlchloroboranes investigated. ... 

In a first step, D-2-amino-2-(1,4-cyclohexadienyl)acetic acid is obtained as follows. A solution of 11.0 g (72.7 mmol) of D-phenylglycine in 900 ml distilled ammonia (which has been treated with 45 mg lithium after distillation to destroy traces of moisture) is slowly diluted with 370 ml dry tert-butyl alcohol. 

Penicilloic acid 5, the substrate for the projected lactamization reaction, could be derived from the suitably protected intermediate 6. Retrosynthetic disassembly of 6, in the manner illustrated, provides D-penicillamine hydrochloride (7) and tert-butyl phthalimido-malonaldehydate (8) as potential building blocks. In the synthetic direction, it is conceivable that the thiol and amino groupings in 7 could be induced to converge upon the electrophilic aldehyde carbonyl in 8 to give thiazolidine 6 after loss of a molecule of water. 

Isocyanide, benzyl, 55, 98 Isocyanide, butyl-, 55, 98 Isocyanide, cyclohexyl-, 55, 98 ISOCYANIDE, 1,1-dimethylethyl- [Isocy-amde, tert-butyl-], 55,96 Isocyanide, dodecanyl- 55,98 Isocyanide, ethyl- 55,98 Isocyanide, methyl-, 55, 98 Isocyanide, phenyl-, 55, 98 1//Isoindole 1,3(2//) dione, 2 amino [Phthahmidc, N-amino-], 55, 115 1//-ISOINDOLE-1,3(2//)-DIONE, trans-( )-2-(2,3-diphenyl-l-aziridinvl)-[Azindine, frans-2,3-diphenyl-l-phthalimido-], 55, 115 ISOXAZOLE, 3-(4-chlorophenyl)-5-(4-methoxy phenyl)-, 55, 39 Isoxazole 5-(4-chlorophenyl)-3-(4-meth-oxyphenyl)-, 55, 42... 

Two phases appear within the first 15 min due to the heavy ionic content of the aqueous layer. Di-tert-butyl iminodicarboxylate, which is produced as a result of the hydrolysis, is selectively soluble in the THF layer, while the amino carboxylate salt of the product remains in solution in the aqueous layer. 

It has been found that the tris(tert-butyloxycarbonyl) protected hydantoin of 4-piperidone 2, selectively hydrolyses in alkali to yield the N-tert-butyloxycarbonylated piperidine amino acid 3. The hydrolysis, which is performed in a biphasic mixture of THF and 2.0M KOH at room temperature, cleanly partitions the deprotonated 4-amino-N -(tert-butyloxycarbonyl)piperidine-4-carboxylic acid into the aqueous phase of the reaction with minimal contamination of the hydrolysis product, di-tert-butyl iminodicarboxylate, which partitions into the THF layer. Upon neutralization of the aqueous phase with aqueous hydrochloric acid, the zwitterion of the amino acid is isolated. The Bolin procedure to introduce the 9-fluorenylmethyloxycarbonyl protecting group efficiently produces 4.8 This synthesis is a significant improvement over the previously described method9 where the final protection step was complicated by contamination of the hydrolysis side-product, di-tert-butyl iminodicarboxylate, which is very difficult to separate from 4, even by chromatographic means. 

THE USE OF POLYSTYRYLSULFONYL CHLORIDE RESIN AS A SOLID SUPPORTED CONDENSATION REAGENT FOR THE FORMATION OF ESTERS SYNTHESIS OF N-[(9-FLUORENYLMETHOXY)CARBONYL]-L-ASPARTIC ACID a tert-BUTYL ESTER, P (2-ETHYL[(lE)-(4-NITROPHENYL)AZO] PHENYL]AMINO]ETHYL ESTER... 

Diboran kann besonders dann zur Reduktion von Nitrilen mit Erfolg eingesetzt werden, wenn Lithiumalanat und auch Lithiumalanat/Aluminiumchlorid nicht die gewunschten Resultate zeigen. Aus tert.-Butyl-malonsaure-dinitril erhalt man z.B. nur durch Reduktion mit Diboran l-Amino-3,3-dimethyl-2-aminomethyl-butan (36—48% d. Th.)2. 

N-tert-butyl-2-[3(S)-amino-2(R)-hydroxy 4-phenylbutyl]-decohydro-(4oS,8aS)-iso-quinoline-3(S)-corboxomide (DC)... 

Alternatively, to avoid difficult separation of diastereomers 18a and epi-18a, the Fmoc-y9 -amino acid of unlike configuration 26 can be obtained as a single dia-stereoisomer in a three-step reaction sequence via conjugate addition of the Li-amide derived from (S)-N-benzyl-l-phenylethylamine (Davies methodology [113]) to tert-butyl tiglate [105] (Scheme 2.3). 

Reacts with vapors of sodium with luminescence at about 260°C. Reacts explosively with thionyl chloride or potassium reacts violently with hexafluoro isopropylidene, amino lithium, ammonia, and strong acids reacts with tert-butyl azidoformate to form explosive carbide reacts with 24-hexadiyn-l, 6-diol to form 2, 4-hexadiyn-l, 6-bischloro-formate, a shock-sensitive compound reacts with isopropyl alcohol to form isopropyl chloroformate and hydrogen chloride thermal decomposition may occur in the presents of iron salts and result in explosion. 

In the reaction of an aminoalcohol with a methyl imidazole-AT-carboxylate or tert-butyl imidazole-AT-peroxycarboxylate, selective acylation of the amino function can be achieved11903 to give the carbamate and peroxycarbamate, respectively, the hydroxy groups of which can be further acylated ... 

Replacement of isopropylamine by tert-butyl amino often results in an increase in potency. This substitution is used in the p-blockers bunitrolol (116),54 bufuralol (117),55 bunolol (118),56 nadolol (119),57 and phenbutalol (120).58 Tazolol (121)59 whose structure is similar, is not a good p-blocker, possessing substantial ISA. 

Syed, J., Forster, S. and Effenberger, F. (1998) Application of the Blaise reaction stereoselective synthesis of (4R)-tert-butyl 3-amino-4-trimethylsilyloxy-2-alkenoates from (R)-cyanohydrins. Tetrahedron Asymmetry, 9, 805-815. 

N-Boc-2-Bromoglycine tert-butyl ester (1), introduced Steglich and coworkers, is a versatile synthon for electrophilic glycine,5 an tnpcDortant tool in the synthesis of non-proteinogenic amino acids. 

Bromo-N-Boc-glycine-tert-butyl ester Acetic acid, bromo[[(1,1-dimethylethoxy)-carbonyl]amino]-, 1,1-dimethylethyl ester, (+)-, (12) (111652-22-3) N-Boc-Glydne-tert-butyl ester Glycine, N-[(1,1-dimethylethoxy)carbonyl)-, 1,1-dimethylethyl ester (12) (111652-20-1)... 

A more complex reaction is involved in the cooligomerization of acetylenes and tert-butyl isocyanide using nickel acetate as the catalyst (Scheme 20)43 the nature of intermediate complexes leading to the formation of 2-cyano-5-terf-butylaminopyrroles has not been established. Cocyclization of tert-butyl isocyanide with coordinated hexafluoro-2-butyne gives rise to coordinated cyclopentadienone anils for molybdenum systems,44 hence the nature of acetylene substitutents and of the organometallic catalyst play crucial roles in these processes. The pyrrole products from the former reaction can be decomposed by sulfuric acid and the overall sequence provides a simple synthesis of 5-amino-2-cyanopyrroles (Scheme 20). 

Unsymmetrical 3,4-dihalo-l,2,5-thiadiazoles 118 and 119 were prepared from 3-amino-4-chloro-l,2,5-thiadiazole 117 via a Sandmeyer-like reaction involving successively tert-butyl nitrite and either copper bromide or copper iodide in anhydrous acetonitrile (Scheme 17) <2003H(60)29>. The bromo and iodo thiadiazoles 118 and 119 undergo selective Stille and Suzuki C-C coupling chemistry (see Section 5.09.7.6). 

X=Br) can be efficiently recovered from aqueous solution of the work-up for reuse.1241 Utilizing this N-anthracenylmethyl technology, various amino add derivatives have been synthesized by Lygo and coworkers in 40-86 % yields with 67-94 % ee as the N-free tert-butyl esters 25 and by Corey and coworkers in 67-91% yields with 92-99.5% ee as the imines 24, respectively. Some representative results are shown in Table 2... 

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