Cuprous butoxide

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. 

METALLATION n-Butyllithium. Cuprous terf-butoxide. N,N,N, N -Tetramethyleth-ylene diamine. 

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

Radicals Bromine azide. -Butyllithium. Cuprous acetate. N,N-Dichlorourethane. 4,4 -Dinilrodiphenylnitroxide. Iodine, oxidation. Iodobenzenedichloride. Manganic tris(acetyl-acetonate) Potassium /-butoxide. Potassium ferricyanide. Potassium mtrosodisulfonate. 

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... 

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. ... 

Titanium tetra-n-butoxide j cuprous chloride jp-toluic acid a,p-Ethyleneoxo compds. ifrom 2-acetylenealcohols Meyer-Schuster rearrangement... 

Iodonitrobenzene added to a soln. of crude cuprous tcrt-butoxide in benzo-thiazole, and heated 20 hrs. at 200° 2-(4-nitrophenyl)benzothiazole. Y 85%. Also with cuprous oxide and f. e. s. J. Chodowska-Palicka and M. Nilsson, Synthesis 1974, 128. 

Cuprous tert-butoxidc allowed to react with a large excess of phenylacetylene at room temp. cuprous phenylacetylide. Y 97%. - Because the basic alkoxide group abstracts an active H-atom with formation of an alcohol, additives to create basic or buffered conditions are not needed. F. e., also with cupric tert-butoxide and a cuprous tert-butoxide-phosphine complex, s. T. Tsuda, T. Hashimoto, and T. Saegusa, Am. Soc. 94, 658 (1972). 

Acetylene derivatives can be conveniently reduced to cw-olefins with magnesium hydride and cuprous iodide or cuprous er -butoxide . 

Also obtained from p-acetoxybenzoyl chloride by treatment with lithium tert-butoxide and tert-butyUithium in a mixture pentane/tetrahydrofurane in the presence of cuprous iodide, followed by hydrolysis (80%) [6683]. 

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