1,2-Aminoalcohol

Products from aminoalcohols and TYZOR TPT were obtained by a2eotropiag the isopropyl alcohol with ben2ene (121,122). From trimethylethylenediamine, dimethylethanolamine, and dimethylisopropanolamine with TYZOR TPT, the orange (11), the yellow (12), and the pale-green (13) were obtained, respectively. The lithium salt of the ligand, derived from C H Li, combiaed with (RO)2TiCl ia hexane has also been used (123). 

The dlenophlle, 3-acetyl-2(3H)-oxazolane, Is an attractive Intermediate for the synthesis of vicinal aminoalcohols with cIs configurations. It reacts with 1,3-dienes, even under quite mild conditions, to form (4+2) cycloadducts. Its high reactivity with deactivated 1,3-dienes Is noteworthy. This property is present also in 2(3H)-oxa201one which can be obtained easily through solvolysis of 3-acetyl-2(3H)-oxa2olone In methanol. 3-Acetyl-2(3H)-oxazolone, on UV irradiation In the presence of a sensitizer, combines easily with olefins to form (2+2) cycloadducts, the hydrolysis of which leads to the class of cis-2-aminocyclobutanols. 

Reactions of benzylic a,P-aminoalcohols and a-hydroxyazindines with Olah s reagent provide a highly efficient way to a P-fluoroamines, a-fluoro-azindines, and ot,Y-difluoroamines [dS] (equations 43 and 44)... 

Reactions of enamines with aluminum hydrogen dichloride (540,541) (UAIH4 and AICI3) or aluminum hydrogen dialkyl compounds (542) led to organoaluminum intermediates which could be hydrolyzed to tertiary amines or oxidized to aminoalcohols. The formation of olefins by elimination of the tertiary amine group has also been noted in these reactions. 

Mammals synthesize phosphatidylserine (PS) in a calcium ion-dependent reaction involving aminoalcohol exchange (Figure 25.21). The enzyme catalyzing this reaction is associated with the endoplasmic reticulum and will accept phosphatidylethanolamine (PE) and other phospholipid substrates. A mitochondrial PS decarboxylase can subsequently convert PS to PE. No other pathway converting serine to ethanolamine has been found. 

A limitation of this approach was the fact that the cyclization could not be accomplished on the resin. This would preclude further functionalization of the core. Therefore an alternate approach was to link the resin to the core via an aminoalcohol spacer as in 93. Furthermore, since linkage was conducted through the P-ketoester component rather than through the nitrogen atom, dihydropyridines 94 could now be formed on the solid support. When the 4-aryl substituent of 94 was nitro, on-resin reduction to the corresponding amine was possible. This allowed for further addition of diversity elements to the core scaffold before cleavage from the resin. 

The carbonyl compound 1 is assumed to react first with amine 2 to give the unstable a-aminoalcohol 5 as intermediate, from which an iminium species 6 is... 

The reaction with organolithium or organomagnesium reagents 9 leads to formation of /3-aminoalcohols 10 ... 

The Mannich reactions plays an important role in pharmaceutical chemistry. Many /3-aminoalcohols show pharmacological activity. The Mannich reaction can take place under physiological conditions (with respect to pH, temperature, aqueous solution), and therefore can be used in a biomimetic synthesis e.g. in the synthesis of alkaloids. 

Incorporation of extensive branching in the side chain similarly does not decrease pharmacologic activity. Reductive alkylation of aminoalcohol, 42, with isobutyraldehyde affords the amine, 43. Acylation of the amine with benzoyl chloride probably goes initially to the amide (44). The acid catalysis used in the reaction leads to an N to 0 acyl migration to afford iso-bucaine (45). ... 

In an analogous sequence, reductive alkylation of aminoalcohol, 46, with cyclohexanone affords the secondary amine (47). Acylation with benzoyl chloride affords hexylcaine (48) in a reaction that may again involve acyl migration. 

Reductive amination of dihydropyran (which may be regarded as the dehydration product of the cyclic acetal of 5-hydroxy-pentanal) in the presence of isopropylamine and a trace of acid affords the aminoalcohol, 96. Treatment of this compound with thionyl chloride affords the haloamine, 97. Alkylation of the quinoline, 92, with this halide yields pentaquine (98). ... 

Treatment of the piperidine 74, obtainable from an aminonitrile such as 73, under N-methylation conditions leads to the dimethylamino derivative 75. The carbobenzoxy protecting group is then removed by catalytic hydrogenation. Reaction of the resulting secondary amine 76 with cyclohexene oxide leads to the alkylated trans aminoalcohol. There is thus obtained the anti-arrhythmic agent transcainide (77) [18]. 

It has been proposed that aziridines may be more widespread in biological systems than is generally realized [190]. Many drugs such as ephedrine (124 Scheme 11.18) and pronethalol (125) and endogenous metabolites such as adrenaline (126) contain a P-aminoalcohol moiety, which may act as a precursor to an aziridine metabolite that may explain the known carcinogenicity of some of these compounds such as pronethalol. 

Nitraminoalcohols. See under Aminoalcohols, Nitrated and Nitrited in Vol 1, A179-L to A180-L... 

Polynuclear complexes with aminoalcohols and iminoalcohols as ligands O-bridged and hydrogen bonded species. J. A. Bertrand and P. G. Eller, Prog. Inorg. Chem., 1976, 21, 29-53 (54). 

Scheme 15 Parallel synthesis of 2-oxazolines from carboxylic acids and aminoalcohols using PS-Mukaiyama reagent...

Aminoalcohols are an important class of compounds in medicinal chemistry because many drugs contain this structure. For their resolution, there are two possibilities acylation of amino function or an enzymatic transesterification with vinyl esters through the hydroxyl group. However, the amino or hydroxyl group must be protected, because if the starting material is the free aminoalcohol, the O- and N-acylation can take place, and in addition, there are migrations obtaining... 

By this concept, a reversible enzymatic aldol reaction generates a mixture of l-threo/erythro aldol diastereomers (133) from which the i-threo isomer is preferentially decomposed by an irreversible decarboxylation to furnish aromatic aminoalcohol (R)-(134) vhth 78% ee in high yield. 

Thioacylation of primary and secondary amines, including aminoacids and aminoalcohols, has been readily carried out from phosphonodithioacetate 28 (R = Et) and the resulting phosphorylated thio amides (thio carbamoyl-... 

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