Alkyl-combinations

Alkylation combines lower-molecular-weight saturated and unsaturated hydrocarbons (alkanes and alkenes) to produce high-octane gasoline and other hydrocarbon products. Conventional paraffin-olefin (alkane-alkene) alkylation is an acid-catalyzed reaction, such as combining isobutylene and isobutane to isooctane. 

The same group [38] also developed a double Heck reaction which was then terminated by a Friedel-Crafts alkylation to give 6/1-54 from 6/1-53 (Scheme 6/1.12) this involved an attack of an alkylpalladium(II) intermediate on an aryl or heteroaryl moiety. Noteworthy is the finding that the formal Friedel-Crafts alkylation occurs on both electron-rich and electron-poor heteroaromatic rings, as well as on substituted phenyl rings. Single Heck/Friedel-Crafts alkylation combinations have also been performed. 

Alkylation Combining Catalytic Unite olefins and isoparaffins Tower isobu-tane/cracker olefin Isooctane (alkylate)... 

Alkylboronic esters, as catalysts, 9, 223 Alkyl-bridged compounds, transition metal-Group 13 alkyl combinations, 3, 271... 

Neopentylidenes, with titantium(IV), 4, 364 Neoplasia, Ti(IV) complex treatments, 4, 664 Nephrosteranic acid, via Ti(IV) complexes, 4, 406 Neutral alkyl-bridged compounds, transition metal-Group 13 alkyl combinations, 3, 271... 

Alkylation combines the lighter FCC products, for example, olefins, usually butylene or a mixture of butylenes and propylene, with a non-olefin, to produce a higher octane gasoline stream. Some aspects of this process, and in particular the still large use of hydrofluoric acid (HF) or sulfuric acid (H2SO4) as the acid catalysts, and related environmental/safety problems have been discussed in the previous section. 

Alkylation Combines FCC low octane reactive molecules (olefins) with a less reactive light component to produce high value, high octane, gasoline component Increases octane yield over either HF or H2SO4 catalysts... 

Alkyl-combination.—Antimony hydride (SbHj), like arsenic hydride (AsHg) and phosphorus hydride (PHj), can give rise to organic compounds in which the H-component is replaced by an alkyl. It is then called stihirte. It can be produced by allowing iodine-alkyls to act upon potassium antimonide or upon sodium antimom de, or by the reaction between antimony chloride and zinc-alkyls. 

Benzothiophenium salts are produced by the reaction of the sulfur heterocycle with more powerful alkylating combinations such as Meerwein salts benzothiophenium salts can themselves act as powerful alkylating agents with fission of the C-S bond. ... 

Iminium ion catalysts have been used to achieve enantioselective alkylation combined with cycUzation. Protected tryptamines react with acrolein under the influence of catalysts 1A7-C [299], Various acroleins with electron-withdrawing substituents at C-3 are also reactive. 

Alkylation units take two small molecules of isobutane and olefin (propylene, butylenes, or pentylenes) and combine them into one large molecule of high-octane liquid called alkylate. This alkylation combining process (Figure 11-8) takes place inside a reactor filled with an acid catalyst. Alkylate is a superior antiknock product that is used in blending unleaded gasoline. 

Various enones could he employed, and only minor electronic effects were observed for R2 substituents. Arylbromide and arylchloride R2 substituents could be used without diminished yields (80-94%). Aryl/alkyl, aryl/aryl, and alkyl/alkyl combinations for R2 and R3 were well tolerated providing functionalized azalactones in good to excellent yields (65-96%) and with high enantio- and diastereoselectivities (75-99% ee, <98 2 dr) (eq 77). Additionally, postfunctionalization of the azalactone products could be explored to generate unnatural quaternary amino acid derivatives and bicyclic dipeptides. 

The quantity of gasoline is increased by cracking (breaking down long hydrocarbon chains) and by alkylation (combining small molecules to make larger ones). 

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