ChemInform Abstract: SYNTHESIS OF ORGANOSULFONYLACETIC ACIDS

Мирскова, А. Н.; Kryukova, Yu. I.; Levkovskaya, G. G.; Guseva, S. A.; Воронков, М. Г.

doi:10.1002/chin.198428158

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“…The residue was refluxed in methanol (5 mL) and concentrated sulfuric acid (250 μL) for 12 h. The cooled solution was poured into ether (5 mL) and washed with water (3 × 5 mL) and an NaHCO 3 solution. The organic phase was dried (MgSO 4 ), evaporated in vacuo, and distilled (Kugelrohr) bp 147 °C (0.1 Torr) [lit . bp 145 °C (0.1 Torr)], to afford 34 as a clear oil (19 mg, 77%): IR (neat) 1749, 1336, 1153, 1087 cm -1 ; 1 H NMR (200 MHz) δ 7.83 (d, J = 8.3 Hz, 2 H), 7.39 (d, J = 8.4 Hz, 2 H), 4.12 (s, 2 H), 3.73 (s, 3 H), 2.48 (s, 3 H).…”

Section: Methodsmentioning

confidence: 99%

“…Compound 11: IR (CH 2Cl2) 1592, 1311, 1153 cm -1 ; 1 H NMR (200 MHz) δ 7.80 (d, J ) 8.1 Hz, 2 H), 7.34 (dd, J ) 8. 1 Hz,2 H),6.23 (s,1 H),2.46 (s,3 H),4 H),4 H),1.54 (s,3 H),1.49 (s,6 H),1.41 (s,3 H),1.32 (s,6 H); mass spectrum, m/z (relative intensity, %) 374 (11, M + ), 219 (47), 177 (23), 135 (39), 91 (100), 77 (85). Anal.…”

Section: -Phenylseleno-2-(p-toluenesulfonyl)ethyne (4)mentioning

confidence: 99%

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Additions of Organocopper Reagents and Heteroatom Nucleophiles to 1-Phenylseleno-2-(p-toluenesulfonyl)ethyne. Preparation of Vinyl and Allenic Sulfones and Formation of Michael, Anti-Michael, and Rearrangement Products

et al. 1998

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1-Phenylseleno-2-(p-toluenesulfonyl)ethyne (4) was produced nearly quantitatively from p-(toluenesulfonyl)ethyne and benzeneselenenyl chloride. It underwent stereo-and regioselective synadditions of organocopper reagents RCu(CN)Li to the -position of the sulfone moiety to afford adducts 5. Further reaction of the products with reagents RCu(SePh)Li resulted in substitution of the phenylseleno group with retention of configuration. Control of E,Z-stereochemistry in the product , -disubstituted vinyl sulfones is therefore achieved by the order of addition of the reagents. Selenoxide syn-elimination of adducts 5 afforded the corresponding allenic sulfones. The additions of amines and alkoxides to 4 produced the corresponding anti-Michael regioisomers (where attack occurred R to the sulfone group) as the major or sole products. The additions were highly stereoselective, proceeding by anti-addition in the anti-Michael series and by syn-addition in the corresponding Michael regioisomers. The reactions of 4 with thiolates and selenolates were more complex, affording rearranged adducts and Michael adducts as the major and minor products, respectively. The formation of the rearranged products can be rationalized by a series of additionelimination processes. Phenylselenoethyne (43) underwent conjugate additions of pyrrolidine, sodium methoxide, sodium ethanethiolate, and benzeneselenolate anion, affording the corresponding cis isomers via anti-addition. The experiments with heteroatom nucleophiles and acetylenes 4 and 43 show that the phenylseleno group has a surprisingly large activating effect upon conjugate additions.Unsaturated sulfones have numerous uses in organic synthesis. 1 The sulfone group, like the carbonyl group, has an activating effect upon an adjacent carbon-carbon double or triple bond with respect to conjugate additions and cycloadditions. The resulting products are saturated or vinyl sulfones that can be further elaborated via reactions of the corresponding sulfone-stabilized R-carbanions with electrophiles. Furthermore, subsequent reductive desulfonylation permits the sulfone moiety to act as a temporary activating group. Thus, for example, acetylenic sulfones function as the synthetic equivalents of dipoles and "multipoles", such as 1 and 2 in Scheme 1.In principle, further opportunities for synthetic transformations that can be used in conjunction with the above become possible if an appropriate nucleofuge is installed at the -position of an acetylenic sulfone. This provides the site for the introduction of an additional nucleophile by substitution of the nucleofuge (Scheme 1) or for the regeneration of unsaturation by its elimination. It appeared to us that the phenylseleno group might be an appropriate -substituent for this purpose, since certain -selenovinyl sulfones are known to undergo substitution reactions of the selenium moiety with organocuprates 2 and other nucleophiles, 3,4 as well as syn-elimination reactions of their corresponding selenoxides. 5,6 We now report the preparation of the novel...

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Section: Methodsmentioning

confidence: 99%

Section: -Phenylseleno-2-(p-toluenesulfonyl)ethyne (4)mentioning

confidence: 99%