Ethylene derivatives boronic acids

It can be seen from the above figure that the present fluoroarylboranes are highly Lewis acidic, however, not as acidic as the most acidic boron or aluminum halides. With respect to crotonaldehyde. the NMR-derived perfluoroarylborane acidities decrease in the order PBB > PNB > FAB. which also reflects the ethylene polymerization activity ordering of this series (vide supra). This acidity measurement is thought to be relatively insensitive to steric effects. However, this ordering of acidity is altered somewhat from results provided by solution reaction calorimetry... 

Peroxydicarbonates s. Diisopropyl peroxydicarbonate Peroxydisnlfate s. Persulfate Peroxymaldc acid 26,136 Peroxymercuration of ethylene derivs. 26, 637 Persolfate 26,137 Peroxytrifluoroacetic acid as reagent 26, 137, 529 —/boron fluoride, oxidations with -, review 19, 161 suppl. 26 pH s. Buffer solns. 

Boronic acid esters from ethylene derivatives G G GHG B(OR)2... 

Phosphoric acid-boron fluoride C-Alkylation of arenes with ethylene derivatives... 

One distinguishes palladium(0)- and palladium(ll)-catalysed reactions. The most common palladium(O) transformations are the Mizoroki-Heck and the cross-coupling transformations such as the Suzuki-Miyaura, the Stille and the Sonogashira reactions, which allow the arylation or alkenylation of C=C double bonds, boronic acid derivates, stan-nanes and alkynes respectively [2]. Another important palladium(O) transformation is the nucleophilic substitution of usually allylic acetates or carbonates known as the Tsuji-Trost reaction [3]. The most versatile palladium(ll)-catalysed transformation is the Wacker oxidation, which is industrially used for the synthesis of acetaldehyde from ethylene [4]. It should be noted that many of these palladium-catalysed transformations can also be performed in an enantioselective way [5]. 

Peroxytrifluoroacetic acid/boron fluoride Ketones from ethylene derivatives with Wagner-Meerwein rearrangement... 

Unsubstituted 20-ketones undergo exchange dioxolanation nearly with the same ease as saturated 3-ketones although preferential ketalization at C-3 can be achieved under these conditions. " 20,20-Cycloethylenedioxy derivatives are readily prepared by acid-catalyzed reaction with ethylene glycol. The presence of a 12-ketone inhibits formation of 20-ketals. Selective removal of 20-ketals in the presence of a 3-ketal is effected with boron trifluoride at room temperature. Hemithioketals and thioketals " are obtained by conventional procedures. However, the 20-thioketal does not form under mild conditions (dilution technique). ... 

Note that ethylbenzene is a derivative of two basic organic chemicals, ethylene and benzene. A vapor-phase method with boron trifluoride, phosphoric acid, or alumina-silica as catalysts has given away to a liquid-phase reaction with aluminum chloride at 90°C and atmospheric pressure. A new Mobil-Badger zeolite catalyst at 420°C and 175-300 psi in the gas phase may be the method of choice for future plants to avoid corrosion problems. The mechanism of the reaction involves complexation of the... 

Dehydration of the optically active relay (178) derived from enmein (62) gave a 1 2 mixture of 5,6-ene and 6,7-ene. Separation could be achieved by means of the ethylene acetal (187), whose ozonolysis product was subjected to successive Jones oxidation, methylation, Wittig reaction, and treatment with dilute hydrochloric acid to afford the 3-on-16-ol derivative (188). Bromination of (188) followed by dehydrobromination and subsequent dehydration afforded (189). The purified compound (189), after conversion into the acetal, was hydrolyzed to carboxylic acid (190), which was transformed into the desired lactone (191) by treatment with boron trifluoride etherate. The reaction produced a single product uncontaminated by the C-1 epimer, because of easy formation of a favored transition state which satisfied the stereoelectronic requirements. 

Electrical conductivity measurements have been reported on a wide range of polymers including carbon nanofibre reinforced HOPE [52], carbon black filled LDPE-ethylene methyl acrylate composites [28], carbon black filled HDPE [53], carbon black reinforced PP [27], talc filled PP [54], copper particle modified epoxy resins [55], epoxy and epoxy-haematite nanorod composites [56], polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blends [57], polyacrylonitrile based carbon fibre/PC composites [58], PC/MnCli composite films [59], titanocene polyester derivatives of terephthalic acid [60], lithium trifluoromethane sulfonamide doped PS-block-polyethylene oxide (PEO) copolymers [61], boron containing PVA derived ceramic organic semiconductors [62], sodium lanthanum tetrafluoride complexed with PEO [63], PC, acrylonitrile butadiene [64], blends of polyethylene dioxythiophene/ polystyrene sulfonate, PVC and PEO [65], EVA copolymer/carbon fibre conductive composites [66], carbon nanofibre modified thermotropic liquid crystalline polymers [67], PPY [68], PPY/PP/montmorillonite composites [69], carbon fibre reinforced PDMS-PPY composites [29], PANI [70], epoxy resin/PANI dodecylbenzene sulfonic acid blends [71], PANI/PA 6,6 composites [72], carbon fibre EVA composites [66], HDPE carbon fibre nanocomposites [52] and PPS [73]. 

A general route to 6-substituted valerolactones (112) is by condensation between aldehydes and the dianion derived from butynoic acid followed by hydrogenation using Lindlar s catalyst.During the synthesis of some steroid derivatives, use has been made of an intramolecular Wadsworth-Emmonds procedure to construct an unsaturated valerolactone group (114) from phos-phonate (113) (c/. 3, 87). A new preparation of ( )-pestalotin (115) has as its pivotal step a Lewis acid-catalysed condensation between 2-benzyloxyhexanol and diketen. /3-Ethylenic valerolactones (116) can be obtained from the corresponding /3-allenic acids by treatment with methanolic boron trifluoride (c/. 3, 89). 

Several solid acid catalysts were tested in the laboratory for the alkylation of ethylene with isobutane following the introduction of the sulfuric acid alkylation process." These were mostly derived from aluminum chloride or boron trifluoride and were never used in the full-scale production of alkylates. 

---