Organic hahdes

A simple and economical route involving the reaction of Hthium metal and organic haHdes was developed in 1930 to prepare organ oHthium compounds such as / -butyUithium (76) ... 

Many organic hahdes, especially alkyl bromides and iodides, react direcdy with tin metal at elevated temperatures (>150° C). Methyl chloride reacts with molten tin metal, giving good yields of dimethyl tin dichloride, which is an important intermediate in the manufacture of dimethyl tin-ha sed PVC stabilizers. The presence of catalytic metallic impurities, eg, copper and zinc, is necessary to achieve optimum yields (108) ... 

The oxidative addition of aHphatic organic haHdes to staimous chloride has long been of interest for the preparation of monoorganotin trihaHdes ... 

AHyl chloride exhibits reactivity as an olefin and as an organic haHde. Its activity as a chloride is enhanced by the presence of the double bond, but its activity as an olefin is somewhat less than that of propylene. AHyl chloride participates in most types of reactions characteristic of either functional group ... 

Tribromoneopentyl-alcohol (TBNPA) is an organic hahde used by the bromine industry as a reactive intermediate for high-molecular-weight flame retardants. This potential contaminant decomposes in an aqueous solution under basic conditions (pH from 7.0 to 9.5), by a sequence of reactions that release one bromide ion... 

In silver-based epoxidations, the role of promoters is to enhance selectivity of epoxide formation. The classic promoters used in industry are cesium and chloride, typically added as the CsCl salt. In some cases, only chloride is added in the form of an organic hahde (e.g., 1,2-dichloroethane). This subject was recently reviewed, so only a short introduction will be given (60). 

Organosodium compounds are prepared from sodium and other organometahic compounds or active methylene compounds by reaction with organic hahdes, cleavage of ethers, or addition to unsaturated compounds. Some aromatic vinyl compounds and aUyhc compounds also give sodium derivatives. 

The kinetics are dependent on the nature of the metal complex and also on the relative amount of initiator. Usually, the organic hahde used as an initiator and the metal compound are employed in a 1 1 molar raho as control of molecular weight is ophmal under these conditions, but higher ratios can also be used [155]. The metal compound is thus effechve in catalytic amounts . It should be noted that by contrast to, for instance, olefin polymerization the metal complexes involved in ATRP are not directly part of the polymerizahon chain growth cycle. Nonetheless, fhey are usually designated as catalysts in the hterature, and fhis des-ignahon is adopted throughout this sechon. 

Oshima and co-workers developed tri(2-furyl)germane (5) as a novel and effective hydrogermane. Triethylborane-induced radical reduction of organic hahdes with 5 provided the corresponding reduced compounds in excellent yields (Scheme 11.16). 

The palladium-catalyzed coupling of organotin compounds with organic hahdes is a powerful method for carhon-carhon bond formation. This procedure is called Migita-Kosugi-Stille coupling [4, 5] and has been widely used for organic synthesis... 

Normal fluids are hydrocarbons, ethers, esters, and many organic hahdes. Strongly hydrogen-bonded substances like water, acetic acid, and hydrogen fluoride are not normal fluids neither are quantum fluids like hehum and hydrogen. Lee and Kesler [2] developed an equation to represent the three-parameter generalized correlation. The equation is presented in Section 4.2.5, entitled Equations of State. Figures 4.7, 4.8, and 4.9 are based on the Lee and Kesler equation. 

A method to fix chloride into CaO under an inert gas (N2, He) stream has been established. For the purpose of reaction system design (reactor and operation conditions), a convenient way to check the stoichiometry for any kind of organic halides is explored. Suppose CHhClx (any organic hahde can be rewritten in this form X and h are integers) reacts with CaO yielding CaCl2, H2O, and possibly C, CaCOa, and H2, depending on flie values of x and h. A reaction temperature between 400°C and 600°C is assumed, and CO2 is fixed as carbonate, while water is evolved from the reactor. The material balance of elements leads to the stoichiometry shown in Table 14.2. 

Comments Any organic hahdes are expressed as Cl molecules in this method. The illustration appears comphcated, but it can cover many reactions at once. 

There is little speculation on the role of Pd(III) in synthesis, although its involvanent in the reactivity of electrochemically generated Pd(I) species has been canvassed as well as its possible role in oxidatively induced decomposition of Pd(II) species by organic hahdes to generate reactive intermediates. ... 

Until recently, cross-coupling between alkylmetals and aryl, alkenyl, and alkynyl halides was achieved mostly with alkylcoppers. Over the past two decades, however, the Ni- or Pd-catalyzed reaction of alkylmetals with the unsaturated organic hahdes mentioned above has been developed as a viable alternative, as detailed in Sect. ni.2.II. The Cu-based methodology still remains highly competitive. So, it is advisable to consider both options for finding the method for a given case. 

A major improvement from a preparative point of view was demonstrated by Mizoroki, Heck, and colleagues, who independently found that organic hahdes were suitable organopalladium precursors, and that the vinylic substitution reaction could be accomplished with a catalytic amount of palladium and a base, in the absence of a reoxidant.t This reaction was developed further by Heck and co-workers and was later referred to as the Heck reaction or Heck olefination.t t The Heck reaction is defined as a vinylic substitution reaction where a vinylic hydrogen is substituted by an aryl, vinyl, or benzyl group (Scheme 2). 

Erase, S. and de Meijere, A. (2004) Cross coupling of organic hahdes with alkenes the Heck reaction, in Metal-Catalyzed Cross-Coupling Reactions, Vol. 1 (eds A. de Meijere and F. Diederich), Wiley-VCH Verlag GmbH, Weinheim, pp. 217-315. 

In contrast to each of the above variations, alkyl iodides may also be utihzed directly in nickel-catalyzed conjugate additions. The mechanism of this class of reactions is not well defined however, the related stoichiometric coupling of enals (e.g., 79) with alkyl halides (e.g., 78) has been demonstrated to proceed through nickel-Jt-aUyl intermediates.l The most widely used variant employs nickel(II) chloride hexahydrate in either catal)hic or stoichiometric quantities with activated zinc as a stoichiometric reductant (Scheme g2) [144-148] pjjg organic hahde may be either sp or sp hybridized, and alkene geometry in the final product (e.g., 80) is maintained with alkenyl iodides. 

Table 3.2. Yields of alcohols from Barbier-type reactions of organic hahdes with lithium and aldehydes in THF as the solvent [15]...

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