Dialkylaluminium chloride

Yoshino reports a novel and general method for the C-3 acylation of indoles with acyl chlorides in the presence of dialkylaluminium chloride which obviates the need for prior N-protection . Interestingly, as described in this preliminary communication, the unprotected indoles 147 are first treated with the Lewis acids prior to addition of the acid chlorides, yielding the desired 3-acyl derivatives 148. In reactions more typical of indoles under acidic conditions, Nakatsuka determined the structures of the dimers and trimers of 1-trimethylacetylindole produced in the presence of aluminium chloride . 

The stereoselective synthesis of /(-branched a-halocarboxylic acids containing two newly formed chiral centres (155) has been accomplished by a reaction consisting of 1,4-addition of dialkylaluminium chlorides to a,/(-unsaturated A -acyloxazolidinones (154) followed by quenching the intermediate aluminium enolate with /V-halosuccini-mides. The most efficient stereo-control was achieved with oxazolidines derived from glucosamine (154). Although /(-branched aliphatic a-halo carboxylic acids were synthesized stereo selectively, the highest stereoselectivity was observed for (3-aryl substrates.112... 

Although low-temperature syndiospecific polymerisation of propylene with soluble Ziegler-Natta catalysts, based on soluble vanadium compounds and dialkylaluminium chlorides as activators, was first carried out successfully as... 

Dialkylaluminium chloride Sulfoximines from iminosulfonyl chlorides... 

Et2AlCl-Assisted Carbonyl Addition. A new method [111] for the preparation of jS-hydroxy-ketones involves the coupled attack of dialkylaluminium chloride and zinc on an a-bromoketone. An aluminium enolate is generated which gives a facile addition to another carbonyl compound, present in the system (illustrated below) ... 

The xylofuranose-derived N-cinnamoyl oxazinone 2 0 reacts with two equivalents of diethylaluminium chloride to deliver the 3-phenyl-valeric acid derivative 21 in high yield (eq. 8). The stereoselection achieved so far is only moderate. A surprising feature of this new 1,4-addition to carboxylic acid derivatives is revealed, when other dialkylaluminium chlorides are used. 

Dialkylaluminium chlorides (acting as Lewis acids) are the preferred catalysts for a number of cyclization reactions, and three further examples reported this year are the conversion of (124) into (125) with MeNC, a process in which... 

Lewis acids such as zinc halides or a dialkylaluminium chloride (AIR2CI) are preferentially used to catalyze the polymerization of acrylics. 

Aldol Reactions.—A new highly effective aldol synthesis employs an aluminium enolate derived regiospecifically from the appropriate a-halogeno-ketone using zinc and dialkylaluminium chloride (Scheme 18). ... 

A new synthetic route to bis(dialkylaluminium) oxides has been developed, involving the condensation of lithium dialkylaluminates with dial-kylaluminium chlorides.373... 

The most commonly and effectively used metal alkyls for propylene polymerization employing magnesium chloride - supported catalysts are invaricibly trlalkylaluminium confounds, dialkylaluminium halide conpounds giving much lower activities. In general the polymerization kinetics shown by catalysts of this type are strongly affected both by the trlalkylaluminium to titanium ratio and by the type of alkylaluminlum compounds which is used. 

The well-known hydroalumination of olefins with dialkylaluminium hydrides can be extended to the addition of diethylaluminium chloride. With diphenylpropene the intermediate (332) is formed, together with ethylene, and yields l,l-diphenylpropan-2-ol in 90% yield on oxidation with H2O2. 

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