Präparative Aspekte elektrophiler Dreikomponentenreaktionen mit Alkenen

Abstract

Preparative Aspects of Electrophilic Three Component Reactions with Alkenes Additions of the electrophilic species Hal+, NO+, NO2+, SO3H+, RS+, HO+, RCO+ and others in the presence of a third nucleophilic agent like H2O, ROH, ROR, RCOOH, RCN, RSCN and others to an alkene leads to many kinds of unsymmetrical vicinal bifunctionalized compounds of preparative value. In the combination of alkenes with electrophilic halogen and f. e. water the products are 2‐halohydrines, with alcohols 2‐haloalkylethers, with carboxylic acids or derivatives 2‐haloalkylesters and with nitriles N‐2‐haloalkylamides. The intramolecular combination of double bond and nucleophilic center in this reaction gives a lot of saturated heterocycles with five or six membered rings, for example halolactones, tetrahydrofurans or‐pyrans, the corresponding thia analogues, oxazolines, thiazolines, imidazolines and others. Transannular reactions often occurs with medium membered cyclodienes or ‐oligoenes and results in interesting heterocycles, like f. e. oxa‐, thia‐ or azabicyclo [4.2.1.] or [3.3.1.] alkanes. Scope and limitations of such reactions with alkenes are given with 287 references.

Direct 1,2‐Oxosulfenylation of Acetylenic Sulfones with DMSO

“…83-85°C, R f = 0.38 (PE/EtOAc 10 : 1, v/v). 1 [22] White solid, yield: 473 mg, 23%; M.p. 118-119°C, R f = 0.41 (PE/ EtOAc 10 : 1, v/v).…”

“…67-68°C, R f = 0.36 (PE/EtOAc 10 : 1, v/v). 1 1-Fluoro-4-((phenylethynyl)sulfonyl)benzene (1 j) [24] White solid, yield: 310 mg, 24%; M.p. 61-63°C, R f = 0.42 (PE/EtOAc 10 : 1, v/v).…”

“…61-63°C, R f = 0.42 (PE/EtOAc 10 : 1, v/v). 1 H NMR (400 MHz, CDCl 3 ) δ 8.13-8.07 (m, 2H, ArH), 7.57-7.45 (m, 3H, ArH), 7.42-7.34 (m, 2H), 7.32-7.22 (m, 2H, ArH). 13 C NMR (101 MHz, CDCl 3 ) δ 166.0 (d, J F-C = 257.4 Hz), 137.9, 132.7, 131.7, 130.42 (d, J F-C = 9.8 Hz), 128.7, 117.7, 116.73 (d, J F-C = 22.9 Hz), 93.7, 85.2.…”

“…Bifunctionalization of unsaturated bonds is an efficient strategy to construct complex compounds or their precursors. Bifunctionalizations of alkenes [1] and alkynes [2] have been well investigated. Bifunctionalizations of alkynes provide structurally diverse products, such as vicinal bifunctionalized alkenes [3] and polycyclic products.…”

[BMIM][PF6] Promotes the Synthesis of Halohydrin Esters from Diols Using Potassium Halides

“…Halohydrin esters are useful building blocks for the preparation of drugs, 1 surfactants, 2 epoxides, 3 epichlorohydrins 4 and nitriles. 5 Some conventional halogenation methods use halogen sources which are pollutants, and generate hazardous halogenated byproducts.…”