Tetrabutylammonium periodate oxidations

Deoxy-l-fluoro-L-glycerol (18) has been prepared by, among other methods, the treatment of 3,4-0-benzylidene-2,5-0-methylene-l,6-di-O-p-tolylsulfonyl-D-mannitol107 (17) with tetrabutylammonium fluoride in acetonitrile, followed by removal of the benzylidene group, periodate oxidation, reduction with borohydride, and hydrolysis. 1,6-Dideoxy-l,6-difluorogalactitol108 was obtained by treatment of 2,3 4,5-di-0-isopropylidene-l,6-di-0-(methylsulfonyl)galactitol with tetra-... 

In another type of oxidative decarboxylation, arylacetic acids can be oxidized to aldehydes with one less carbon (ArCH2COOH — ArCHO) by tetrabutylammonium periodate. 23l< Simple aliphatic carboxylic acids were converted to nitriles with one less carbon (RCH2COOH — RC=N) by treatment with trifluoroacetic anhydride and NaNCU in FjCCOOH.239 See also 4-39. 

Polymer supported sodium ruthenate is able to catalyze the oxidation of alcohols with iodosobenzene or tetrabutylammonium periodate in CH2CI2.8 It is not clear whether the primary oxidant is ruthenate or perruthenate. 

Tetrabutylammonium periodate in the refluxing mixed solvent toluene/methanol (5/1 by volume) cleanly oxidizes the sulfides to sulfoxides. When three equivalents of tetrabutylammonium periodate were used, the test sulfides 2-dodecyl thiolane and 2-dodecyl thiane were >99% converted after a 20-minute reflux to the corresponding sulfoxides (98%) and sulfones (2%). After 60 minutes the yield of sulfone had increased to 10%. The reaction is highly dependent on the exact conditions employed. Small deviations from the recommended conditions may produce unacceptable results (24). Sulfones of saturated sulfides are difficult to reduce (22) and thus their generation should be minimized for maximum recovery of the sulfides. 

The sulfides and sulfoxides can be interconverted. Oxidation of the sulfides with either photochemically-generated singlet oxygen or preferably with tetrabutylammonium periodate ( ) selectively oxidizes the sulfides to the sulfoxides and reduction of the sulfoxides with LiAlH4 converts them to the sulfides. (For these and other analytical methods, cf. Reference 7) Reduction of the sulfoxides with LiAlH4 showed that the resultant sulfides were identical to the native sulfides isolated from the aromatic fraction of the oil. 

Enantioselective total syntheses of (-)-6-epitrehazolin and (+)-trehazolin were achieved by the synthesis of 275, which began with an asymmetric heterocycloaddition between [(benzyloxy)methyl]cyclopentadiene (263),108 prepared from thallous cyclopentadienide, and the acylnitroso compound arising from in situ oxidation of (,S )-mandelohydroxamic acid (264) with tetrabutylammonium periodate. Cycloaddition led to a mixture of 265 and its diastereomer (Scheme 35).109 The inseparable mixture was reduced to afford cyclopentenes 266 and 268 in 40% and 11 % overall yields, respectively, from thallous cyclopentadienide. Catalytic osmylation of 266 favored syn addition, while the osmylation of diacetate 267 was more selective and nearly quantitative, affording, after acetylation, compounds 270 and 269 in >5 1 ratio. 

Tetrabutylammonium periodate, (C4H9)4N104 (mp 175 °C dec), which is usually prepared in situ from tetrabutylammonium hydrogen sulfate and sodium periodate [776], is useful in two-phase systems, because it dissolves in chloroform and other organic solvents. Its scope and limitations resemble those of periodic acid and alkaline periodates the oxidation of carboxylic acids [777] and a-hydroxy acids [776, 778] to aldehydes with one less car-... 

Degradative oxidation of acids to aldehydes with one less carbon is achieved by tetrabutylammonium periodate. Phenylacetic acids give benz-aldehydes in 50-85% yields when refluxed with the reagent in dioxane [777]. 

Tetrahydrothiophene (tetramethylene sulfide) gives tetramethylene sulfoxide in 90% yield on refluxing for 2 h with tetrabutylammonium periodate [776]. The oxidation of tetramethylene sulfide with one equivalent of hydrogen peroxide at room temperature affords tetramethylene sulfoxide with two equivalents at refluxing temperature, tetramethylene sul-fone is obtained (equation 559) [164]. 

Therefore, the classical rrani-dioxoRu(VI) - oxoRu(IV) catalytic cycle [2] (Fig. 1) can be ruled out as the primary reaction pathway in case of rapid catalytic oxygenation. The apparent zero-order kinetics observed are consistent with a steady-state catalytic regime accessible from different initial states of ruthenium metalloporphyrin. Indeed, common oxidants, other than aromatic iV-oxides, such as iodosylbenzene, magnesium monoperoxyphthalate, Oxone and tetrabutylammonium periodate produced the trans-dioxoRu(VI) species from Ru (TPFPP)(CO) under reaction conditions but were ineffective for the rapid catalysis. 

Periodates have been used in a variety of oxidations. Tetrabutylammonium periodate can be used in nonaqueous media to oxidize alcohols to aldehydes (60-97% yields),... 

Oxygen Nucleophile. Uchiro et al. have reported hydrolysis of a thioglycoside bond under very mild conditions using the combination of tetrabutylammonium periodate as oxidant, trityl tetrakis(pentafluorophenyl)borate as Lewis acid catalyst, and HMDO in anhydrous acetonitrile at 0 °C (eq 17). The reaction also proceeded well in the absence of HMDO, using aqueous tri-flic or perchloric acid as catalyst in place of the trityl derivative. The intersaccharidic bond of a disaccharide was found to be stable under these conditions, with no anomerization being observed. 

Tetrabutylammonium periodate in chloroform oxidatively decarboxylates a-hydroxy-acids to aldehydes. The reaction is cleaner and faster than oxidation... 

Polyaniline has also been prepared in acetonitrile and chloroform solvents using Fe(C104)3 and tetrabutylammonium periodate as the oxidant, respectively. ... 

E-Stilbene (0.181 g, 1 mmol) was dissolved in 1 2 acetonitrile DMM (15 mL). To this solution were added buffer (10 mL, 0.05 M solution of Na2B4O7l0H2O in 4 x 10-4 M aqueous Na2(EDTA)), tetrabutylammonium hydrogen sulfate (0.015 g, 0.04 mmol), and ketone catalyst (77.4 mg, 0.3 mmol). The mixture was cooled in an ice bath. A solution of Oxone (0.85 g, 1.38 mmol) in aqueous Na2(EDTA) (4 x 10-4 M, 6.5 mL) and a solution of K2CO3 (0.8 g, 5.8 mmol) in water (6.5 mL) were added dropwise separately over a period of 1.5 h (via syringe pumps or addition funnels). The best results were obtained if these solutions were added in a steady, uniform manner. After 2 h, the reaction was diluted with water (30 mL), and extracted with hexanes (4 x 40 mL). The combined extracts were washed with brine, dried (Na2S04), filtered, concentrated, and purified by FC on silica gel (previously buffered with 1% triethylamine solution in hexane) using 1 0 to 50 1 hexane ether as eluent. This provided trans-stilbene oxide (0.153 g, 78%) with 98.9% ee. 

---