Oximes sulfonates

The treatment of 2-hydroxyacetophenone with hydroxylamine-O-sulfonic acid in dilute aqueous base produced 3-methyl-1,2-benzisoxazole. The mechanism was reported to be a C(2)—C(3) ring closure via intermediate (560) (Scheme 171). Salicylaldehyde failed to cyclize with dilute base, but with 20% KOH and hydroxylamine-O-sulfonic acid the transformation to 1,2-benzisoxazole succeeded (76MI41600). Kemp and Woodward isolated an oxime sulfonate (561) from salicylaldehyde and hydroxylamine-O-sulfonic acid and the subsequent decomposition gave 1,2-benzisoxazole in 95% yield (65T3019). 

If the rearrangement of oxime sulfonates is induced by organoaluminum reagents,the intermediate (71) is captured by the nucleophile originally attached to the Al. By this means an oxime can be converted to an imine, an imino thioether (R—N—C—SR), or an imino nitrile (R—N—C—In the last case, the nucleophile comes from added trimethyl si lyl cyanide. The imine-producing reaction can also be accomplished with a Grignard reagent in benzene or toluene. ... 

Reaction between oxime sulfonates and organometallic compounds... 

Reaction between an oxime sulfonate, an organoaluminum compound, and Mc3SiCN... 

Aldicarb nitrile, see Aldicarb Aldicarb nitrile sulfone, see Aldicarb Aldicarb nitrile sulfoxide, see Aldicarb Aldicarb oxime, see Aldicarb Aldicarb oxime sulfone, see Aldicarb Aldicarb oxime sulfoxide, see Aldicarb Aldicarb sulfone, see Aldicarb Aldicarb sulfone acid, see Aldicarb Aldicarb sulfone alcohol, see Aldicarb Aldicarb sulfone aldehyde, see Aldicarb Aldicarb sulfone amide, see Aldicarb Aldicarb sulfone oxime, see Aldicarb Aldicarb sulfoxide, see Aldicarb Aldicarb sulfoxide acid, see Aldicarb Aldicarb sulfoxide alcohol, see Aldicarb Aldicarb sulfoxide aldehyde, see Aldicarb Aldicarb sulfoxide amide, see Aldicarb Aldicarb sulfoxide nitrile, see Aldicarb Aldicarb sulfoxide oxime, see Aldicarb Aldrin, see Dieldrin Aldrin diol, see Aldrin Alkyl hydroperoxides, see Acetaldehyde Allyl alcohol, see Allyl chloride, l,2-Dibromo-3-chloropropane, 1,2-Dichloropropane Allylbenzene, see Isopropylbenzene p-(2-Atnino-3-nitrophenyl)glucopyranoside, see 2-Nitroaniline Allyl chloride, see Allyl alcohol, l,2-Dibromo-3-chloropropane, 1,2-Dichloropropane 2-Aminobenzimidazole, see Benomvl... 

Rajagopal et al. (1984) used numerous compounds to develop a proposed pathway of degradation of aldicarb in soil. These compounds included aldicarb oxime, A-hydroxymethyl aldicarb, A-hydroxymethyl aldicarb sulfoxide, A-demethyl aldicarb sulfoxide, A-demethyl aldicarb sulfone, aldicarb sulfoxide, aldicarb sulfone, A-hydroxymethyl aldicarb sulfone, aldicarb oxime sulfone, aldicarb sulfone aldehyde, aldicarb sulfone alcohol, aldicarb nitrile sulfone, aldicarb sulfone amide, aldicarb sulfone acid, aldicarb oxime sulfoxide, aldicarb sulfoxide aldehyde, aldicarb sulfoxide alcohol, aldicarb nitrile sulfoxide, aldicarb sulfoxide amide, aldicarb sulfoxide acid, elemental sulfur, carbon dioxide, and water. Mineralization was more rapid in aerobic surface soils than in either aerobic or anaerobic subsurface soils. In surface soils (30 cm depth) under aerobic conditions, half-lives ranged from 20 to 361 d. In subsurface soils (20 and 183 cm depths), half-lives under aerobic and anaerobic conditions were 131-233 and 223-1,130 d, respectively (Ou et al, 1985). The reported half-lives in soil ranged from approximately 70 d (Jury et ah, 1987) to several months (Jones et al, 1986). Bromilow et al. (1980) reported the half-life for aldicarb in soil to be 9.9 d at 15 °C and pH 6.34-7.0. 

Another synthetic route via the Beckmann rearrangement, which is promoted by organoaluminum reagent along with alkylation, involves a new stereoselective reduction of the imino group. The starting oxime sulfonate (228) was synthesized from cyclopentanone (226) in three steps Reaction of 226 with 1-undecene in the presence of silver oxide produced the a-undecylcyclopentanone (227) which on successive treatment with hydroxylamine and methanesulfonyl chlo-ride-triethylamine gave the mesylate (228). Treatment of the oxime mesylate... 

As oxime derivatives, oxime sulfonates can be used preferentially for the following reasons (1) they are readily available from oximes using p-... 

PREPARATION OF a -ALKYLATED AMINES FROM OXIME SULFONATES WITH TRIALKYLALUMINUM - DIISOBUTYLALUMINUM HYDRIDE... 

As oxime derivatives, oxime sulfonates can be used preferentially for the following reasons (1) they are readily available from oximes using p-toluenesulfonyl chloride or methanesulfonyl chloride in the presence of base in almost quantitative yield, (2) they are easy to handle because of their fine crystalline properties, (3) they are sufficiently reactive to initiate the rearrangement by organoaluminum reagents. 

As shown in Table I, this reaction sequence has wide generality and is readily applicable to the straightforward synthesis of various naturally occurring alkaloids such as coniine,9 pumiliotoxin C,11 1 and solenopsin A and B.11 Oxime sulfonates of either linear or cyclic structures may be used. Obviously, the regioselectivity of the reaction follows the general rule of... 

A particularly photosensitive oxime sulfonate surface coating composition was prepared by this group (5) consisting of an oxime tetrabutylammonium sulfonate salt, (VI), which had an E0 of 0.17 mJ/cm2. 

Pyrolysis of alkyl or aryl azides 8-18 Reaction between oxime sulfonates and organometallic compounds... 

Oxaziridines, 276, 277 2-Oxazolidones, chiral, 379-381 2-Oxazoline-5-ones, 151 Oxazolines, 147, 265, 588 Oxime sulfonates, 245-246 jx-Oxobis(chlorotriphenylbismuth), 381-382 Oxodiperoxymolybdenum(pyridine)(hexamethyl phosphoric triamide), 382-383 p,3-Oxohexakis( x-triinethylacetato)trimethanol-triiron(ffl), 382-383 a-Oxoketene dithioacetals, 185 Oxomethoxymolybdenum(V) 5,10,15,20-totraphcnylpoiphyrin, 383 Oxone, 442 Oxosulfenylation, 205... 

Beckmann rearrangement.3 Reaction of oxime sulfonates with simple Grignard reagents in dry toluene at —78° results in imines, which can be reduced to a-alkylamincs or alkylated with allylic or propargylic Grignard reagents to furnish a,a-diulkylnmincs. 

Beckmann rearrangement-alkylation sequenceOxime sulfonates react with AIR, to form rearranged imines, which are reduced to amines by DIBAH (equation I). The reaction involves selective migration of the R group anti to the oxime sulfonate. 

The Neber rearrangement of oxime sulfonates has been considered to proceed via a nitrene pathway or an anion pathway. If the latter mechanism is operative, the use of a certain chiral base might result in the discrimination of two enantiotropic a-protons to furnish optically active a-amino ketones. Verification of this hypothesis was provided by realizing the asymmetric Neber rearrangement of simple oxime sulfonate 83,... 

One significant (and indeed the first) preparative pathway to this ring system is the Neber rearrangement of oxime sulfonates. Recently it has been shown that this process can be mildly influenced by the introduction of chiral auxiliaries. Thus, rearrangement of the tosyl oxime 186 (formed in situ from the oxime 185) in the presence of catalytic amounts of the chiral quaternary... 

Another significant preparative pathway to the 2i/-azirine system is the Neber rearrangement of oxime sulfonates. The presence of strong electron-withdrawing groups in the a-position to the oxime increases the acidity of those protons, and thus favors the cycloelimination reaction under mild conditions. The Neber reaction occurs either through an internal concerted nucleophilic displacement or via a vinyl nitrene (Scheme 213) <2001EJ02401>. 

Diisobutylaluminum phenylselenolate (39), which is prepared in situ by the reaction between diphenyl diselenide and diisobutylaluminum hydride (DIBALH) [67], is also a useful nucleophilic selenium reagent (Scheme 37). For example, 39 reacts with oxime sulfonates to produce selenoimidic esters... 

Treatment of a wide variety of oxime sulfonates with several equivalents of alkyl-aluminum reagents in CH2CI2 resulted in formation of the imines, which were directly reduced with excess DIBAH to give the corresponding amines, as shown in Sch. 19. This organoaluminum-promoted Beckmann Rearrangement of oxime sulfonates has been successfully applied to the stereoselective synthesis of naturally occurring alkaloids, pumiliotoxin C, and solenopsin A and B, as illustrated in Sch. 20 [43]. 

Combination of silyl enol ethers with the organoaluminum-promoted Beckmann rearrangement of oxime sulfonates resulted in a novel reaction system that leads to the formation of enaminones [44]. Treatment of a mixture of anfr-2-methylcyclohexa-none oxime sulfonate (33) and 2-(trimethylsiloxy)-l-octene in dry CH2CI2 with Et2AlCl at -78 °C for 30 min, and at 20 °C for additional 1 h resulted in formation of the enaminone 34 in 90 % yield (Sch. 21). 

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