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The Charette modification replaces the CH 2 I 2 normally found in the Simmons–Smith reaction with aryldiazo compounds, such as phenyldiazomethane, in Pathway A. [30] Upon treatment with stoichiometric amounts of zinc halide, an organozinc compound similar to the carbenoid discussed above is produced. This can react with almost all alkenes and ...
Zinc is a strong reducing agent with a standard redox potential of −0.76 V. Pure zinc tarnishes rapidly in air, rapidly forming a passive layer. The composition of this layer can be complex, but one constituent is probably basic zinc carbonate, Zn 5 (OH) 6 CO 3. [8] The reaction of zinc with water is slowed by this passive layer.
The reaction produces a primary, secondary, or tertiary alcohol via a 1,2-addition. The Barbier reaction is advantageous because it is a one-pot process: the organozinc reagent is generated in the presence of the carbonyl substrate. Organozinc reagents are also less water sensitive, thus this reaction can be conducted in water.
Zn(CN) 2 is easy to make by combining aqueous solutions of cyanide and zinc ions, for example via the double replacement reaction between KCN and ZnSO 4: [5] ZnSO 4 + 2 KCN → Zn(CN) 2 + K 2 SO 4. For commercial applications, some effort is made to avoid halide impurities by using acetate salts of zinc: [5] [6] Zn(CH 3 COO) 2 + HCN → Zn(CN ...
The Reformatsky reaction (sometimes transliterated as Reformatskii reaction) is an organic reaction which condenses aldehydes or ketones with α-halo esters using metallic zinc to form β-hydroxy-esters: [1] [2] The Reformatsky reaction. The organozinc reagent, also called a 'Reformatsky enolate', is prepared by treating an alpha-halo ester ...
The relative amounts depend on reaction conditions, which can be optimized to favor one or the other. [2] For instance, if this reaction is conducted in pentane at -40 °C, (η 5-C 5 Me 5)ZnEt is the sole product. Conversely, if the reaction is conducted in diethyl ether at -10 °C, (Zn 2 (η 5-C 5 Me 5) 2) is the major product.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Water-reactive substances [1] are those that spontaneously undergo a chemical reaction with water, often noted as generating flammable gas. [2] Some are highly reducing in nature. [ 3 ] Notable examples include alkali metals , lithium through caesium , and alkaline earth metals , magnesium through barium .