Primary, Secondary, and Tertiary Aliphatic Alcohols

There is little influence of ligand bulk on alkoxovanadate formation, and reaction of vanadate with secondary alcohols is not disfavored when compared to primary 

It is not clear what the chemical shift of -559 ppm corresponds to. It is close to that of monoanionic vanadate, -560 ppm, but cannot be said to correspond to that chemical shift. Possibly, it corresponds to some species that in the presence of water leads to vanadate but, in aqueous alcoholic solution, also generates an alkoxovanadate. 

There is little information available on the complexation of alcohols by live- or six-coordinate vanadium(V) compounds. Complexes of ethanolamine do form heteroligand products with alcohols [12], The formation constants for these materials are in the order of 0.2 to 0.5 M 1 and, therefore, are not very different from similar formation constants observed for alkoxovanadates. 

Chemical Shifts (ppm) Observed and Calculated for Monoanionic Vanadate Complexes of Aliphatic Alcohols (ROH)a 

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Acidic clays are widely applied in the dehydration of alcohols [38]. Although similar to zeolites in their capacity to induce the formation of both alkenes and ethers, selective alkene synthesis is possible. Various layered materials (clays, ion-exchanged montmorillonite, pillared layered clays) are very active and, in general, selective in transforming primary, secondary, and tertiary aliphatic alcohols to 1-alkenes [39-43]. Al -exchanged montmorillonite, however, induces ether formation from primary alcohols and 2-propanol [41]. Substituted 1-phenyl-1-ethanols yield the corresponding styrene derivatives at high temperature (653-673 K) [44]. 

Scheme 5.2 illustrates the use of super acid media in the study of carbonium ion generation, structure, and reactions by NMR spectroscopy. The behavior of primary, secondary, and tertiary aliphatic alcohols on being dissolved in FS03H-SbF5-S02 at... 

Scheme 5.3 illustrates the use of superacid media in the study of carbonium ion generation, structure, and reactions by NMR spectroscopy. The behavior of primary, secondary, and tertiary aliphatic alcohols on being dissolved in FS03H-SbF5-S02 at —60 C provides direct support for the dictum that tertiary carbonium ions are more stable than secondary, which are more stable than primary. Primary and secondary alcohols are protonated under these conditions, and the protonated alcohols are the species observed (entry 1), while tert-butyl alcohol yields tert-butyl cation at rates too... 

Halogenation of Alcohols, The combination of POCI3 and DMF can be used to halogenate primary, secondary, and tertiary aliphatic alcohols (eq 14), whereas the reaction of primary alcohols and POCI3 without DMF or DMA will generally lead to the formation of trialkyl phosphates. 

A similar approach was simultaneously investigated by Bols et al. Initially thio-glycoside 25 was reacted with Me2SiCl2 and primary, secondary, or tertiary aliphatic alcohols or phenol in the presence of pyridine to produce the corresponding silyl acetals 26a-26d in good yields (Scheme 9). Activation of 26a-26d with NIS and a catalytic amoimt of TfOH resulted in exclusive formation of a-glucopyrano-sides 28a-iBd [20]. 

A broad range of compounds can be O-alkylated with carbene complexes, including primary, secondary, and tertiary alcohols, phenols, enols, hemiaminals, hydroxylamines, carboxylic acids, dialkyl phosphates, etc. When either strongly acidic substrates [1214] and/or sensitive carbene precursors are used (e.g. aliphatic diazoalkanes [1215] or diazoketones) etherification can occur spontaneously without the need for any catalyst, or upon catalysis by Lewis acids [1216]. 

The reaction of alcohols with diarylcarbodiimides [16, 35, 36] is catalyzed by sodium alkoxides but not by triethylamine. Recently Schmidt and Moos-miiller [37, 38] found that cuprous chloride (0.075 mole/100 mmole dialkyl-carbodiimide) catalyzes the reaction of primary, secondary, and tertiary alcohols with aliphatic carbodiimides to give O Af -trialkylpseudoureas. Several examples of the use of these methods are described in Tables I and II. 

A one-pot reaction has been developed for the reduction of aldehydes, ketones, and primary, secondary and tertiary alcohols into their corresponding alkyl function using either diethylsilane or n-butylsilane as the reducing agent in the presence of the Lewis acid catalyst tris(pentafluorophenyl)borane carbon-carbon double bonds remain unaffected.366 Aliphatic and aromatic polycarboxylic acids are also conveniently reduced to their corresponding alkanes using the same reagents and catalyst.367... 

An alternative method for the formation of acyl hypoiodites, developed by Barton, involves the treatment of the acid with r-butyl hypoiodite. Subsequent white light photolysis in benzene at room temperature gave good yields of it ides from primary, secondary and tertiary acids (equation 21). The method was not applicable in the presence of alcohols. A more recent technique involving hypervalent iodine is due to Suarez primary, secondary or tertiary aliphatic acids are heated to reflux in tetrachloromediane with iodosylbenzene diacetate and iodine resulting in good yields of iodides. The method is mild and, with obvious exceptions such as unprotected alcohols, is tolerant of many functional groups, as illustrated in equation (22). ... 

Phenol was hydroxylated with TS-1 and hydrogen peroxide to give a 1 1 mixture of catechol (4) and hydroquinone (5) (Eqn. 21.6).26>29 Anisole and other substituted benzenes gave similar results. Secondary and tertiary aliphatic C-H bonds were oxidized to give alcohols and ketones, but primary C-H bonds were... 

Very similar results to those described with propyne can be obtained with a wide variety of other alkynes, e. g., acetylene, higher aliphatic and aromatic alkynes as well as other nucleophilic reagents, such as water, aliphatic (primary, secondary, and tertiary) and aromatic alcohols, thiols, and amines. 

USE For prepn of standard NaNOj soln for water analy -sis prepn of aliphatic nitro-compds as reagent for primary, secondary, and tertiary alcohols. 

Acyloxy-4,6-dimethoxy-[l,3,5]-triazines 301, obtained by reaction between carboxylic acids and CDMT 137, have been used as acylating agents for the synthesis of esters from primary, secondary, and tertiary alcohols (Scheme 59). Because of the mild acylation conditions, the method could be applied to esterification of labile alcohols with aromatic and aliphatic acids in good yields <1999S593>. 

An early study of cyclic amine acidities by Hall [189] using Hammett constants produced good linear plots for the pK s, while a study of aliphatic amines using Taft constants also produced linear plots, with separate lines for the primary, secondary, and tertiary amines [190]. Ballinger and Long [191] found a linear correlation between the pK s of a number of alcohols and Taft o values, with p = 1.42 for the dissociation reaction, errin [182] later summarized acidity results using Hammett constants for benzene derivatives in the expressions... 

A more efficient and more generahy applicable cobalt-catalysed Mizoroki-Heck-type reaction with aliphatic halides was elegantly developed by Oshima and coworkers. A catalytic system comprising C0CI2 (62), l,6-bis(diphenylphosphino)hexane (dpph 73)) and Mc3 SiCH2MgCl (74) allowed for intermolecular subshtution reactions of alkenes with primary, secondary and tertiary alkyl hahdes (Scheme 10.25) [51, 53]. The protocol was subsequently applied to a cobalt-catalysed synthesis of homocinnamyl alcohols starting from epoxides and styrene (2) [54]. 

Fig. 10.3. The general appearance of the C—O region for aliphatic and aromatic ethers, for primary, secondary and tertiary alcohols, and for phenols. Often we see band clusters rather than single bands, as these vibrations involve interacting C—O and C—C stretch of various types, and other group vibrations as well.

Catalytic systems have been developed for the synthesis of primary, secondary, and tertiary amines from alcohols. Preparation of primary amines has been performed by hydrogen autotransfer mono-eoupling of ammonia to alcohols (Scheme 12.2). Milstein, Vogt, and Beller have all reported conditions for the mono-allq lation of ammonia with benzylie and aliphatic alcohols. Vogt s and Beller s protocols permit the use of seeondary aleohols, providing access to aZp/ra-branched primary amines. Beller s Ru/xantphos system is also suitable for the diamination of diols and the eonversion of hydrory esters to primary amino esters. 

Secondary aliphatic alcohols 3625-3620 (s) 1350-1260 (s) 1125-1085 (s) See comments under primary aliphatic alcohols Also for a-unsaturated and cyclic tertiary aliphatic alcohols... 

Another Rh-catalyzed protocol that has potentially broad utility has come from the reactions of Cu(i) alkoxides with allylic carbonates.190,191 Under the action of Wilkinson s catalyst modified by P(OMe)3, a variety of primary, secondary, and even tertiary aliphatic alcohols undergo an allylic etherification process with a high degree of retention of regio- and stereochemistry, thus providing expeditious access to a and/or ct -stereogenic ether linkages (Scheme 5).192... 

Few studies have systematically examined how chemical characteristics of organic reductants influence rates of reductive dissolution. Oxidation of aliphatic alcohols and amines by iron, cobalt, and nickel oxide-coated electrodes was examined by Fleischman et al. (38). Experiments revealed that reductant molecules adsorb to the oxide surface, and that electron transfer within the surface complex is the rate-limiting step. It was also found that (i) amines are oxidized more quickly than corresponding alcohols, (ii) primary alcohols and amines are oxidized more quickly than secondary and tertiary analogs, and (iii) increased chain length and branching inhibit the reaction (38). The three different transition metal oxide surfaces exhibited different behavior as well. Rates of amine oxidation by the oxides considered decreased in the order Ni > Co >... 

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