Alcohol heterocyclic secondary

Varieties of primary and secondary alcohols are selectively oxidized to aldehyde or carbonyl compounds in moderate to excellent yields as summarized in Table 3. As can be seen, /(-substituted benzyl alcohols (e.g., -Cl, -CH3, -OCH3, and -NO2) yielded > 90% of product conversion in 3-4 h of reaction time with TOP in the range of 84-155 h (entries 2-5, Table 3), Heterocyclic alcohols with sulfur- and nitrogen-containing compoimds are found to show the best catalytic yield with TOP of 1517 and 902 h for (pyrindin-2-yl)methanol and (thiophene-2-yl) methanol, respectively (entries 9 and 10, Table 3). Some of aliphatic primary alcohols (long chain alcohols) and secondary alcohols (cyclohexanol, its methyl substituted derivatives and norboman-2-ol) are also selectively oxidized by the membrane catalyst (entries 11-14 and 15-17, Table 3) with TOP values in the window of 8-... 

Chen C, Zhang Y, Hongs H (2011) V-heterocyclic carbene based ruthenium-catalyzed direct amide synthesis from alcohols and secondary amines involvement of esters. J Org Chem... 

Carboie lic acids have also been utilised as electrophiles for N-alkylation. Beller reported the reaction of primary or secondary amines with carboxylic acids in the presence of a platinum catalyst and phenylsilane to directly provide the products of reductive amination. The proposed mechanism involves initial amide formation followed by reduction to the amine. A diverse range of functional groups are tolerated, including olefins, alcohols, heterocycles, and esters (Scheme 12.15). 

A white solid, m.p. 178 C. Primarily of interest as a brominaling agent which will replace activated hydrogen atoms in benzylic or allylic positions, and also those on a carbon atom a to a carbonyl group. Activating influences can produce nuclear substitution in a benzene ring and certain heterocyclic compounds also used in the oxidation of secondary alcohols to ketones. 

The most versatile derivative from which the free base can be readily recovered is the picrate. This is very satisfactory for primary and secondary aliphatic amines and aromatic amines and is particularly so for heterocyclic bases. The amine, dissolv in water or alcohol, is treated with excess of a saturated solution of picric acid in water or alcohol, respectively, until separation of the picrate is complete. If separation does not occur, the solution is stirred vigorously and warmed for a few minutes, or diluted with a solvent in which the picrate is insoluble. Thus, a solution of the amine and picric acid in ethanol can be treated with petroleum ether to precipitate the picrate. Alternatively, the amine can be dissolved in alcohol and aqueous picric acid added. The picrate is filtered off, washed with water or ethanol and recrystallised from boiling water, ethanol, methanol, aqueous ethanol, methanol or chloroform. The solubility of picric acid in water and ethanol is 1.4 and 6.23 % respectively at 20°. 

Heterocyclic compounds that have water bound covalently across a C=N bond behave as secondary alcohols. When subjected to very gentle oxidative conditions, they are converted into the corresponding 0x0 compounds. Potassium permanganate in 0. IN sodium hydroxide at room temperature has been used to oxidize 2- and 6-hydroxypteri-dine to 2,4- and 6,7-dihydroxypteridine, respectively. In contrast, 4-hydroxypteridine was not attacked by this reagent even at 100°. Hydrogen peroxide in acid solution was used to oxidize quinazoline quinazoline 3-oxide 1,3,5-, 1,3,7-, and 1,3,8-triazanaphthalene and pteridine (which hydrate across the 3,4-double bond in the... 

The activating effect of a trichloromethyl group is seen in the 2-dechlorination reactions of 2-chloro-4,6-bis(trichloromethyl)-s-tria-zine (175) with arylsulfonylhydrazides (24 hr) and heterocyclic amines (3 hr) at 20° and with unbasifled primary and secondary alcohols (65°, 30 min). The 4,6-diphenyl or 4,6-bis(4-chlorophenyl) analogs do not react in this manner. ... 

In recent years, extensive attention has been focused on finding cultured plant cells that can be used as catalysts for organic functional group transformations. A number of transformations employing freely suspended or immobilized plant cell cultures have been reported.24 For example, Akakabe et al.25 report that immobilized cells of Daucus carota from carrot can be used to reduce prochiral carbonyl substrates such as keto esters, aromatic ketones, and heterocyclic ketones to the corresponding secondary alcohols in ( -configuration with enantiomeric excess of 52-99% and chemical yields of 30 63%). 

The catalytic activity of Cp Ir(III) complexes in the Oppenauer-type oxidation of alcohols was considerably enhanced by the introduction of N-heterocyclic carbene ligands. Here, high turnover numbers (TONs) of up to 950 were achieved in the oxidation of secondary alcohols [40]. 

Chiral l,3-dioxin-4-ones photochemically react intermolecular with (cyclic) ethers, acetals, and secondary alcohols to give the addition products in reasonable yields. The radical addition was completely stereoselective at C-6 of the heterocycle <1999EJO1057>. The exocyclic diastereoselectivity, where relevant, was about 2 1 (Equation 30). In analogy, an intramolecular cascade reaction of a 1,3-dioxin -one derived from menthone was used to get a terpenoid or a steroid framework in optically active form <1997JA1129, 1999JA4894>. 

Organometallic reagents are better known for their involvement in the alkylations at ring nitrogen atoms in many heterocycles. However, under proper circumstances, they can promote addition to carbonyl groups. Such is the case when 68 is allowed to react with an excess of Me2BuMgLi at 0°C. The secondary alcohol 69 is obtained in fair yield (Equation 28) <20040L1991>. 

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