Aluminum Acetylide

As an alternative to the Grignard reagent system noted previously,38 aluminum acetylides react selectively with mixed halide/ester species to replace only the halide (Equation 4.18).49... 

Ethyl 2,3-epoxypropanoate is a very interesting chiron. It may be opened by various organometallic compounds such as dialkyl, diaryl, and divinyl lithium cuprates, dialkylmagnesium cuprates, trialkylalanes and aluminum acetylides.5 6 The epoxide ring is attacked regiospecifically at the p-position and produces a-hydroxy esters exclusively without racemization. The same result is observed with... 

Aluminum Acetylide, Al2(Cj)s, wh solid, prepd by direct action of acetylene on Al pdr at 450-500°. It is a true acetylide because on hydrolysis it gives C2H2... 

Aluminum Corbide. See Aluminum Acetylide and Aluminum Carbide under Acetylides Aluminum Chlorate. See under Chlorates Aluminum Chloride. See under Chlorides Aluminum Chloride-Nitromethone Complex. 

Ethynylnickel compounds, prepared from aluminum acetylides and nickel acetylace-tonate pretreated with diisobutylaluminum hydride, also undergo insertions with a, 8-unsaturated carbonyl compounds to form enolates which hydrolyze to 4-ynones . Similarly, vinylnickel derivatives from vinylzirconium compounds and nickel acetylace-tonate add to a, 8-unsaturated ketones to give enolates ... 

Indole synthesis starting from 2-unsubsituted anilines represents an atom-economical synthetic route that utilizes more readily available substrates. The Yamamoto group developed a method for nucleophilic introduction of alkynyl groups at the ortho position of the aniline moieties of A-phenylhydroxyamine derivatives 214 using aluminum acetylides 215 (Scheme 19.56) [101]. They applied this chemistry successfully to indole synthesis using Castro s conditions (Cul in DMF) to obtain indoles 217. 

Zhou Y, Lecourt T, Micouin L (2010) Direct synthesis of l,4-disubstituted-5-alumino-1,2,3-triazoles copper-catalyzed cycloaddition of organic azides and mixed aluminum acetylides. Angew Chem Int Ed 49 2607-2610... 

Cyclic A-sulfinyliminium salts 72 are another new type of highly activated substrates for aluminum acetylide additions and were also introduced by Royer... 

Formation and Reaction of Alkynylaluminum Reagents. Lithium acetylides react with Et2AlCl to form LiCl and diethylaluminum acetylides. The aluminum acetylides are useful reagents for carrying out Sn2 reactions on epoxides (eq 8) and undergo conjugate addition to enones that can adopt an S-cis conformation (eq 9). ... 

Formation and Reaction of Alkynylaluminum Reagents. Lithium acetylides react with Me2AlCl to give dimethylaluminum acetylides that react analogously to the more commonly used diethylaluminum acetylides (see Diethylalu-minum Ethoxyacetylide). Addition of the aluminum acetylide to propiolactone results in an Sn2 reaction to give an alkynic acid (eq 1) ... 

---