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They produced and test marketed a line of hand tools branded with their own name. In 1981, the company was acquired by Emerson Electric. [3] In the late 1990s, Western Forge moved its screwdriver production to a plant in Murphy, North Carolina. In April 2006, it closed the Murphy plant and consolidated its operations in Colorado Springs, citing ...
The main limitation of the traditional Wittig reaction is that the reaction proceeds mainly via the erythro betaine intermediate, which leads to the Z-alkene. The erythro betaine can be converted to the threo betaine using phenyllithium at low temperature. [18] This modification affords the E-alkene. The Schlosser variant of the Wittig reaction
In order to obtain the E-alkene, the Schlosser modification of the Wittig reaction can be performed." That agrees with the general description in the "Classical mechanism" section, which accompanies the mechanism leading to 7 (a Z form).
For stabilized Wittig reagents bearing conjugated electron-withdrawing groups, even relatively weak bases like aqueous sodium hydroxide or potassium carbonate can be employed. [Ph 3 PCH 3] + Br −, typical phosphonium salt. The identification of a suitable base is often an important step when optimizing a Wittig reaction.
Modified Wittig–Claisen tandem reaction is a cascade reaction that combines the Wittig reaction and Claisen rearrangement together. The Wittig reaction generates the allyl vinyl ether intermediate that further participates in a Claisen rearrangement to generate the final γ,δ-unsaturated ketone or aldehyde product (Figure "Modified Wittig ...
There exists solid-supported modifications of the reaction. [4] [1] [5] Similar to the Wittig reaction, the reaction suffers from issues with triphenylphosphine oxide by-product removal. Such an issue is mitigated via catalytic aza-Wittig-reactions, some of which entail elements other than phosphorus, like arsenic and tellurium [5] [6].
In 1958, Leopold Horner published a modified Wittig reaction using phosphonate-stabilized carbanions. [2] [3] William S. Wadsworth and William D. Emmons further defined the reaction. [4] [5] In contrast to phosphonium ylides used in the Wittig reaction, phosphonate-stabilized carbanions are more nucleophilic but less basic. Likewise ...
Apex Tool Group is an American supplier of hand tools and power tools. It was formed as a joint venture of Cooper Industries and Danaher by the merger of Cooper Tools and Danaher's Tools and Components segment.