Amido alcohol

Potassium and sodium borohydride show greater selectivity in action than lithium aluminium hydride thus ketones or aldehydes may be reduced to alcohols whilst the cyano, nitro, amido and carbalkoxy groups remain unaffected. Furthermore, the reagent may be used in aqueous or aqueous-alcoholic solution. One simple application of its use will be described, viz., the reduction of m-nitrobenzaldehyde to m-nitrobenzyl alcohol ... 

As many natural and synthetic /3-lactams bear 3-acylamino substituents, the corresponding free amines or protected forms thereof are versatile synthetic intermediates. They may be prepared in several ways, for example by deacylation of the 7-amido group in naturally occurring penicillins by enzymic or chemical means. Chemical degradation usually involves conversion of the amide to a chloroimidate followed by cleavage with aqueous alcohols (75S547 p. 560, 78T1731 p. 1753). 

The behavior of unsaturated azlactones with organometallic reagents has been studied in detail. Arylmagnesium halides and phenyllithium attack 4-arylidene-5-oxazolones at the carbonyl carbon to give ring-opened amido tertiary alcohols (26) and oxazolines (27) (by ring closure), usually as mixtures [Eq. (17)]. The nature of the... 

Quatemized imidazolines with an amido moiety are suitable formulations for general oil and gas field applications. The synthesis of such compounds is detailed in the literature [1218]. For aqueous systems that contain sulfide compounds, a mixture has been described [262] that consists of an aqueous solution of an alcohol such as diethylene glycol monobutyl ether, butyl cellosolve, additional orthophosphoric acid, a fatty acid (from tall oil), substituted imidazoline, an ethoxylated fatty diamine (polyamines such as ethylenediamine, diethylenetriamine, etc.), and a molybdate compound. 

No details are given for scheme A. Presumably one could use the phosphoryl chloride instead of the fluoride. Scheme B, in which ethyl chloride is formed, was run in boiling xylene using equimolar quantities of the reactants. Michaelis (33) has partially described the preparation of starting materials from secondary amines with phosphorus oxychloride and also ethyl dichlorophosphate. Schrader (38) obtained alkyl and amido fluophosphates by reaction of the corresponding chlorophosphates with sodium fluoride in aqueous or alcoholic solution. 

Ostensibly minor variations of a synthetic procedure sometimes can have significant consequences. For example, substituting KOCMe(CF3)2 for LiOC-Me(CF3)2 is believed [85] to lead to formation of the alkylidyne complex shown in Eq. 16 instead of the known [83] Mo(CH-f-Bu)(NAd)[OCMe(CF3)2]2 (Ad=ad-amantyl). A proton is likely to be transferred before formation of the final product, since it has been known for some time that both W(CH-f-Bu)(NAr)[OC-Me(CF3)2]2 and W(C-f-Bu)(NHAr)[OCMe(CF3)2]2 are stable species that cannot be interconverted in the presence of triethylamine [41]. In such circumstances the nucleophilicity of the alkoxide ion and the nucleophilicity and acidity of the alcohol formed upon deprotonation of the alkylidene will be crucial determinants of whether the imido nitrogen atom is protonated at some stage during the reaction. At this stage few details are known about side reactions in which amido alkylidyne complexes are formed. 

Noyori and coworkers reported well-defined ruthenium(II) catalyst systems of the type RuH( 76-arene)(NH2CHPhCHPhNTs) for the asymmetric transfer hydrogenation of ketones and imines [94]. These also act via an outer-sphere hydride transfer mechanism shown in Scheme 3.12. The hydride transfer from ruthenium and proton transfer from the amino group to the C=0 bond of a ketone or C=N bond of an imine produces the alcohol or amine product, respectively. The amido complex that is produced is unreactive to H2 (except at high pressures), but readily reacts with iPrOH or formate to regenerate the hydride catalyst. 

Increasing interest is expressed in diastereoselective addition of organometallic reagents to the ON bond of chiral imines or their derivatives, as well as chiral catalyst-facilitated enantioselective addition of nucleophiles to pro-chiral imines.98 The imines frequently selected for investigation include N-masked imines such as oxime ethers, sulfenimines, and /V-trimcthylsilylimines (150-153). A variety of chiral modifiers, including chiral boron compounds, chiral diols, chiral hydroxy acids, A-sull onyl amino acids, and /V-sulfonyl amido alcohols 141-149, have been evaluated for their efficiency in enantioselective allylboration reactions.680... 

Hiroi et al. also reported the Cp lr complex-catalyzed Oppenauer-type oxidation of primary alcohols in acetone and butanone [31]. These authors prepared a novel Ir-ligand bifunctional catalyst 6 having an amido-alkoxo ligand, the... 

Fig. 3. Structure of an MIM with a tetracarboxylic core. C polycarboxylic core of MIM GI first layer of triiodinated rings. I3 triiodinated aromatic ring G2 second layer of triiodinated rings. L amido-acetyl bond G3 third layer of triiodinated rings. AA amino alcohol...

Amido alcohol functional groups increase the surface hydrophilicity and thereby reduce interactions with biological membranes or proteins. The amino alcohols chosen (HNR1R2, where Rj and R2 each have at least one hydroxyl group) must provide the best compromise between hydrophilic coverage and viscosity while retaining high solubility. 

Oxidation of A-acyltyramines 264 with IBTA proceeds with intramolecular participation of amido group oxygen in nonnucleophic solvents to give spiro-oxazines 265 (Scheme 66, route a ). In nucleophilic solvents such as alcohol or acetic acid, addition of solvent at the para position occurs to give quinone 266 (Scheme 66, route b ) (91JOC435). 

Numerous HCLA have been developed and used for the enantioselective isomerization of oxiranes to allylic alcohols and, in most cases, their efficiency strongly depends on the structure of the oxirane. The HCLA species can be divided into two groups monohthiated vicinal diamines or ether-amines and dilithiated diamines or amido-alcoholates. 

Structurally very close to the N,N,O-tridentate ketiminate systems, magnesium complexes bearing bis-amido-oxazolinate complexes 44a-e were used in the PLA preparation from L-lactide in the presence of benzyl alcohol. The low reactivity of 44d, e is due to the presence of a pendant functionality engaging the metal center, and the steric bulk of the phenyl group hindering the coordination of benzyl alcohol or of a monomer to the metal center, contributing to a diminution of the propagation [69]. 

Figure 13.10 Synthesis of mannose-/glucose-functionalized dendrimers. For dendrimer loading, x + y = 50% loading was used because optimal activity for glycodendrimers with concanavalin A was previously determined to occur at 50% functionalization. Remaining amines from the poly(amido amine) (PAMAM) substrate were capped as alcohols.

Syntheses of amido- and peptido-fluoroketones have been reviewed (Figure 7.46). The main problems concern enantio- and diastereoselectivity, and also the oxidation step of a fluorinated amino alcohol, which is generally required. Indeed, the peptidic couplings required for the edification of parts Pi, P2, etc. cannot be... 

Nucleophilic ring opening of 2-phenyl-5(4//)-oxazolone 146 with (15, 2/f)-l-aminoindan-2-ol provides an amido alcohol that, upon treatment with... 

Derivatives of the steroids androstene and pregnene have been transformed directly into A-acyl amino acids by an orthogonal catalysis procedure, utilizing [RhCl(nbd)]2 and Co2(CO)8 (Scheme 11). The rhodium phosphine catalyst (generated in situ in the presence of syn-gas and phosphine) affects hydroformylation of the internal olefin to generate aldehyde. In the presence of Co2(CO)8, A-acyl amino acids are obtained as the major products. An unstable amido alcohol intermediate, formed by reaction of the amide with aldehyde, is proposed to undergo cobalt-catalyzed GO insertion to yield the desired A-acyl amino acid. 

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