Cuprous r-butoxide

Table 6 Acylation of Heterocupiate Reagents Derived from Organolithiums and Cuprous r-Butoxide...

Cyclopropanes. In the presence of cuprous r-butoxide complexed with tri-/i-butylphosphine, methyl a-chloropropionate and methacrylonitrile react to form the isomeric cyclopropanes (1) and (2) via organo-copper intermediates. No reaction occurs in the absence of the ligand. This reaction was carried out... 

Another hydride, magnesium hydride prepared in situ from lithium aluminum hydride and diethylmagnesium, reduced terminal alkynes to 1-alkenes in 78-98% yields in the presence of cuprous iodide or cuprous r rt-butoxide, and 2-hexyne to pure cij-2-hexene in 80-81% yields [///]. Reduction of alkynes by lithium aluminum hydride in the presence of transition metals gave alkenes with small amounts of alkanes. Internal acetylenes were reduced predominantly but not exclusively to cis alkenes [377,378]. 

The catalyst system for the coupling reaction was a Pd(II)-tri-phenylphosphine complex, usually prepared in situ, with excess triphenyl-phospUne and either cuprous iodide or cupric acetate as a co-catalyst. Alternatively, a preformed catalyst mixture prepared from these reagents may be utilized (see Experimental Section). When 2-methyl-3-butyn-2-ol was used as the protected acetylene, the intermediates 5a-d were converted to the corresponding aryl acetylenes 6a-d by a retro-Favorskii-Babayan (8) reaction utilizing potassium r-butoxide in toluene under conditions of slow distillation. In the case of p-iododimethylaniline (3e), trimethylsilylacetylene was used as the ethynyl source. The intermediate (5e) was treated with hydroxide to generate the free aryl acetylene 6e. The syntheses of 6d and 6e are described in the Experimental section below. 

DIENES Dichloromalcic anhydride. DITERPENES Palladium catalysts. OLEFINS Cuprous chloride. Lithium di-phenylphosphide. Lithium orthophosphate. Potassium r-butoxide. Thiophe-nol-Azobuty toni tide. OXASPIROPENTANE Lithium iodide. 

Reduction of alkynes. This reagent reduces alkynes stereoselectively to the corresponding c/i-alkenes alkanes are not formed. Typical yields are 80-957 . Cuprous iodide can be replaced by copper(I) r-butoxide with equally satisfactory results. ... 

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