Iodide, cuprous reagents

ALLYLIC ALCOHOLS Benzeneselenol. 9-Borabicyclo[3.3.11 nonane. n-Butyllithium. Cuprous iodide-Grignard reagents. Diethylaluminum 2,2,6,6-tetramethylpiperidide. Fluorodimethoxyborane. rrans-l-Tri-n-butylstannyl-propene-3-tetrahydropyranyl ether. 

Until recently, the magnesium, lithium, and, to a lesser extent, cadmium compounds were the only organometallic systems of much use in organic synthesis. This situation has changed drastically in the last few years. Compounds of copper have proven to be especially valuable. One of the first examples of these compounds is a reagent prepared from methyllithium and cuprous iodide this reagent is referred to as lithium dimethylcuprate. The reagent adds selectively at the /3-carbon... 

Cuprous iodide catalyzes the reaction of various alkyl chlorides, bromides, and iodides in hexamethylphosphoric triamide (HMPT), to give the complexed product RaSnXj, which can then be further alkylated with a Grignard reagent, or can be hydrolyzed to the oxide and converted into various other compounds, R2SnY2 (43). This promises to be a useful laboratory method, e.g.,... 

Alkyl bromides and especially alkyl iodides are reduced faster than chlorides. Catalytic hydrogenation was accomplished in good yields using Raney nickel in the presence of potassium hydroxide [63] Procedure 5, p. 205). More frequently, bromides and iodides are reduced by hydrides [505] and complex hydrides in good to excellent yields [501, 504]. Most powerful are lithium triethylborohydride and lithium aluminum hydride [506]. Sodium borohydride reacts much more slowly. Since the complex hydrides are believed to react by an S 2 mechanism [505, 511], it is not surprising that secondary bromides and iodides react more slowly than the primary ones [506]. The reagent prepared from trimethoxylithium aluminum deuteride and cuprous iodide... 

The above-mentioned study was followed by a report of the groups of Ji, Loh and coworkers, who reported the application of a catalyst based on cuprous iodide and Tol-BINAP for the same purpose . Noteworthy is that the effective use of a C2-symmetric ligand in this reaction marks the end of the aforementioned metal-differentiating coordination concept. It was shown that a variety of Grignard reagents could be used for the... 

Organocuprate reagents (another source of carbanion equivalents) are obtained by the reaction of one equivalent or cuprous iodide with two equivalents of an organolithium reagent ... 

The lithium dialkylcuprate (also called a Gilman reagent) is formed by the reaction of two equivalents of the corresponding organolithium reagent (Section 10-8B) with cuprous iodide ... 

Lithium dialkylcuprate reagents (Gilman reagents) are formed by the reaction of two equivalents of an organolithium reagent with cuprous iodide. Reaction of the dialkylcuprate with an alkyl, aryl, or vinyl halide forms a new carbon-carbon bond. 

Cuprous iodide, Cul Reacts with organolithiums to yield lithium diorganocopper reagents (Gilman reagents Section 10.8). 

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. 

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