Sodium periodate, reaction with alkenes

Osmium tetroxide used in combination with sodium periodate can also effect alkene cleavage.191 Successful oxidative cleavage of double bonds using ruthenium tetroxide and sodium periodate has also been reported.192 In these procedures the osmium or ruthenium can be used in substoichiometric amounts because the periodate reoxidizes the metal to the tetroxide state. Entries 1 to 4 in Scheme 12.18 are examples of these procedures. Entries 5 and 6 show reactions carried out in the course of multistep syntheses. The reaction in Entry 5 followed a 5-exo radical cyclization and served to excise an extraneous carbon. The reaction in Entry 6 followed introduction of the allyl group by enolate alkylation. The aldehyde group in the product was used to introduce an amino group by reductive alkylation (see Section 5.3.1.2). 

Trithioles and 1,3,2-dioxathiolanes. 1,2,3-Trithiolanes are prepared by reaction of alkenes with elemental sulfur . The synthesis of 1,3,2-dioxathiolane -oxides (cyclic sulfites) and 1,3,2-dioxathiolane S, -dioxides (cyclic sulfates) is discussed in comprehensive reviews <1997AHC(68)89, 2000T7051>. The most widely used method for the preparation of 1,3,2-dioxathiolane A-oxides 557 is the reaction of the corresponding 1,2-diols 556 with thionyl chloride in the presence of pyridine or triethylamine (Scheme 251). More reactive 1,3,2-dioxathiolane S,A-dioxides 558 are usually obtained by oxidation of sulfites 557 with sodium periodate, which is mediated by ruthenium tetroxide generated in situ from a catalytic amount of ruthenium trichloride <1997AHC89, 2000T7051, CHEC-III(6.05.10.3)183>. 

V. Mirkhani, M. Moghadam, S. Tangestaninejad, H. Kargar, Mn(BrsTPP)Cl supported on polystyrene-bound imidazole An efficient and reusable catalyst for biomimetic alkene epoxidation and alkane hydroxylation with sodium periodate under various reaction conditions, Appl. Catal. A 303 (2006) 221. 

Other reactions that involved [Mn(TNH2PP)Cl MWCNT] as catalytic nanoreactor are the oxidation with sodium periodate of 2-imidazolines in MeCN [174] and the oxidative decarboxylation of a-arylcarboxylic acids with sodium periodate [175] (Scheme 14.8 a,b). On the other hand, iron(lll) me o-tetra(2-chlorophenyl)porphyrin, coordinated to hydroxyl-functionalyzed MWCNTs, catalyzed the oxidation of alkanes, alkenes, and sulfides using tetrabutylammo-nium peroxomonosulfate (BU4NHSO5) as oxygen source [176] (Scheme 14.8c). 

In summary, the reaction of osmium tetroxide with alkenes is a reliable and selective transformation. Chiral diamines and cinchona alkakoid are most frequently used as chiral auxiliaries. Complexes derived from osmium tetroxide with diamines do not undergo catalytic turnover, whereas dihydroquinidine and dihydroquinine derivatives have been found to be very effective catalysts for the oxidation of a variety of alkenes. OsC>4 can be used catalytically in the presence of a secondary oxygen donor (e.g., H202, TBHP, A -methylmorpholine-/V-oxide, sodium periodate, 02, sodium hypochlorite, potassium ferricyanide). Furthermore, a remarkable rate enhancement occurs with the addition of a nucleophilic ligand such as pyridine or a tertiary amine. Table 4-11 lists the preferred chiral ligands for the dihydroxylation of a variety of olefins.61 Table 4-12 lists the recommended ligands for each class of olefins. 

Sodium periodate (sodium metaperiodate), NaI04 (mp 300 °C dec), which is commercially available, is applied mainly in aqueous or aqueous-alcoholic solutions. Like the free periodic acid, sodium periodate cleaves vicinal diols to carbonyl compounds [762], This reaction is especially useful in connection with potassium permanganate [763, 764] or osmium tetroxide [765], Such mixed oxidants oxidize alkenes to carbonyl compounds or carboxylic acids, evidently by way of vicinal diols as intermediates. Sulfides are transformed by sodium periodate into sulfoxides [322, 323, 766, 767, 768, 769, 770, 771, 772], and selenides are converted into selenoxides [773]. Sodium periodate is also a reoxidant of lower valency ruthenium in oxidations with ruthenium tetroxide [567, 774],... 

The results of some oxidations with potassium permanganate differ depending on the pH of the reaction. For example, stearolic acid gives 9,10-diketostearic acid at pH 7-7.5 (achieved with carbon dioxide) and azelaic acid on treatment at pH 12 [864]. In some reactions, potassium permanganate is used as a catalyst for oxidation with other oxidants, such as sodium periodate. Thus alkenes are cleaved to carbonyl compounds or acids via vicinal diols obtained by hydroxylation with potassium permanganate, followed by cleavage by sodium periodate [763, 552]. 

Oxidation of the hydroxymalonic acid ene adducts with cerium(IV) ammonium nitrate in aqueous acetonitrile or sodium periodate results in oxidative didecarboxylation to give an allylcarboxylic acid. The two step process ene reaction with diethyl oxomalonate and oxidative didecarboxylation provides a general procedure for the conversion of alkenes to allylcarboxylic acids. 

Furthermore, pyrazol-3-ones have been oxidized by a variety of oxidizing agents such as ozone in oxygen, hydrogen peroxide solution, 3-chloroperbenzoic acid, aqueous sodium periodate, lead(IV) acetate with boron trifluoride etherate, or atmospheric oxidation. The reactions lead mainly to epoxidation of an alkene or imine functionality and cleavage of the pyrazol-3-one ring. 

Further studies showed that using a combination of sonication and phase-transfer catalyst (PTC) the rate and yield of the reaction of alkene with dichlorocarbene which resulted from chloroform and sodium hydroxide pellets in situ could be improved efficiently [40], Compared with the results reported by Regen [41 ] where sonication alone was used, they found that mechanical stirring was not necessary under high-power sonication. Other findings included the fact that the ratio of NaOHialkene could be decreased from 10 1 to 3 1 and the reaction period could be shortened from 5 h to 10—15 min in the presence ofO. 1-0.05% PTC. 

A similar method was used to generate dibromocarbene using a combination of sonication and PTC for the reaction of alkene with dibromocarbene formed from bromoform and solid sodium hydroxide in situ [42], Compared with the preparation of dichlorocarbene, however [39], the amount of PTC required had to be increased 10-fold. The combination of the effect of sonication and PTC was significant in that the presence of PTC allowed a shortening of the reaction period to 20-30 min and an increase in yield to 96% compared with 3 h and 40-50% using sonication alone. 

The hydroboration of alkynes with (9-BBN)2 exhibits kinetics similar to those for the hydroboration of alkenes. The kinetics are studied (1) by pumping the reaction mixture through a sodium chloride IR cell and monitoring the disappearance of B-H bridges of (9-BBN)2 at 1,570 cm" by quantitative IR spectrometry [Ij and (2) by quenching the aliquots of the reaction mixture periodically with excess methanol and analyzing by GLC for residual alkyne. For the more... 

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