Organic compounds, unsaturated

Nickel is a moderately lustrous, silvery metal, and is extensively used in alloys (for example coinage, stainless steel) and for plating where a durable resistant surface is required. It is also used as an industrial catalyst, for example in the hydrogenation of unsaturated organic compounds. It is attacked by dilute aqueous acids but not by alkalis it combines readily with many non-metals on heating. 

Mercury(II) nitrate Acetylene, aromatics, ethanol, hypophosphoric acid, phosphine, unsaturated organic compounds... 

Diels-Alder Reaction. In 1928, Diels and Alder discovered that 1,3-unsaturated organic compounds reacted with quinoid systems to give partially hydrogenated, cycHc compounds. In the course of their work, they found that 1 mol of 1,4-naphthoquinone [130-15-4] reacted readily with 1 mol of 1,3-butadiene [106-99-0] to give a partially hydrogenated anthraquinone (11) l,4,4a,9a-tetrahydro-9,10-anthracenedione [56136-14-2] which, on oxidation with chromic oxide, produced anthraquinone (43) ... 

R SiH and CH2= CHR interact with both PtL and PtL 1. Complexing or chelating ligands such as phosphines and sulfur complexes are exceUent inhibitors, but often form such stable complexes that they act as poisons and prevent cute even at elevated temperatures. Unsaturated organic compounds are preferred, such as acetylenic alcohols, acetylene dicarboxylates, maleates, fumarates, eneynes, and azo compounds (178—189). An alternative concept has been the encapsulation of the platinum catalysts with either cyclodextrin or in thermoplastics or siUcones (190—192). 

Unsymmetrical functional tetraorganotins are generally prepared by tin hydride addition (hydrostaimation) to functional unsaturated organic compounds (88) (see Hydroboration). The realization that organotin hydrides readily add to atiphatic carbon—carbon double and triple bonds forming tin—carbon bonds led to a synthetic method which does not rely on reactive organometatiic reagents for tin—carbon bond formation and, thus, allows the synthesis of... 

With Unsaturated Compounds. The reaction of unsaturated organic compounds with carbon monoxide and molecules containing an active hydrogen atom leads to a variety of interesting organic products. The hydroformylation reaction is the most important member of this class of reactions. When the hydroformylation reaction of ethylene takes place in an aqueous medium, diethyl ketone [96-22-0] is obtained as the principal product instead of propionaldehyde [123-38-6] (59). Ethylene, carbon monoxide, and water also yield propionic acid [79-09-4] under mild conditions (448—468 K and 3—7 MPa or 30—70 atm) using cobalt or rhodium catalysts containing bromide or iodide (60,61). 

H. Ozonizalion of organic compounds. The ozonization of each unsaturated organic compound is more or less an individual problem, but some general comments may be made. Organic ozonides are highly explosive, and hence it is safest to carry out the ozonization in a solvent which dissolves both the original compound and the ozonide. In all cases, a shatterproof screen of laminated safety glass should be placed between the operator and the tubes H, I, and J. A second screen should be placed back of the tubes to protect other pieces of the apparatus. 

Because of their selectivity, molecular sieves offer advantages over silica gel, alumina or activated charcoal, especially in their very high affinity for water, polar molecules and unsaturated organic compounds. Their relative efficiency is greatest when the impurity to be removed is present at low concentrations. Thus, at 25° and a relative humidity of 2%, type 5A molecular sieves adsorb 18% by weight of water, whereas for silica gel and alumina the figures are 3.5 and 2.5% respectively. Even at 100° and a relative humidity of 1.3% molecular sieves adsorb about 15% by weight of water. 

The basis of this method is to react a compound containing Si—H groups with unsaturated organic compounds. For example, ethylene may be reacted with trichlorosilane... 

Selenium diimides react in a manner similar to SeOa with unsaturated organic compounds. The first report of BuN=Sc=N Bu described its use as an in situ reagent for allylic amination of olefins and acetylenes. Improved procedures for this process (Eq. 10.5) and for the diamination of 1,3-dienes (Eq. 10.6) have been developed using the reagents RN=Se=NR [R = para-toluenesulfonyl (Ts), ort/io-nitrobenzenesulfonyl (Ns)]. ... 

Cyclic Oi anic Compoimds Unsaturated Organic Compounds ... 

Addition polymers are formed by the reaction of the monomeric units without the elimination of atoms. The monomer is usually an unsaturated organic compound such as ethylene, H2C=CHs, which in the presence of a suitable catalyst will undergo an addition reaction to form a long chain molecule such as polyethylene. A general equation for the first stage of such a process is... 

Unsaturated organic compounds that are present in the solution while these reactions proceed will also become adsorbed on the electrode and may act as acceptors for the radicals, yielding addition products ... 

Pioneering work involving the combinahon of an organosulfide, a C-C unsaturated organic compound and a transihon metal catalyst was reported by Reppe in 1953, in which Ni(CO)4-catalyzed hydrothiocarboxylahori of alkyne or ethylene by thiol and CO was briefly described to give the corresponding thioesters 1 or 2 (an application of one of the so-called Reppe reachons) (Eqs. 7.1 and 7.2) [12, 13]. 

Although these reactions indicated the great potenhal of transihon metal-catalyzed reachons of organosulfides with C-C unsaturated organic compounds, little attenhon has been paid to such a combination of reactions for many years since then. In 1960, Holmquist and Carnaham reported the Co-catalyzed reachon of thiol with CO (1000 atm) at 250-300°C to afford thioester 3 in up to 46% yield with ca. 1-5 wt% of catalyst (Eq. 7.3) [14]. 

Although the path (a) has been verified by a stoichiometric reaction [23], the details of exact reaction mechanism remain unsettled. Triggered by this publication [and the Pd-catalyzed doublethiolation of alkynes described in Eq. (7.7) in Section 7-3], a number of transition metal-catalyzed additions of S-X or Se-X bonds to C-C unsaturated organic compounds started to be published. In 1994, BackvaU et al. applied the Pd(OAc)2-catalyzed hydrothiolation to conjugated enynes and obtained 17,... 

Although the selectivity of the reaction was unsatisfactory, this is, to my knowledge, the first documentation describing the transition metal catalyzed doublethio-latiorf of C-C unsaturated organic compounds. 

Tozer, D. J., Amos, R. D., Handy, N. C., Roos, B. O., Serrano-Andres, L., 1999, Does Density Functional Theory Contribute to the Understanding of Excited States of Unsaturated Organic Compounds , Mol. Phys., 97, 859. 

Oxidative addition reactions have been observed also for the binuclear clusters of other d-transition elements with multiple M-M bonds [1,116,117]. The multiplicity of the M-M bonds must decrease in these reactions. It is known from organic chemistry that similar reactions are extremely characteristic of unsaturated organic compounds. We believe that the capacity for oxidative... 

In commercial-scale epoxidation of unsaturated organic compounds, 50-70% hydrogen peroxide is added dining 2-8 h to the stirred mixture of unsaturated compound, aliphatic acid and acid catalyst at 50-80°C, the rate of addition being... 

Matheson (1975) and Hart and Anbar (1970) note the following characteristics of the reaction of ehwith unsaturated organic compounds ... 

It has been known from the earliest observations in gold chemistry that olefins form very weak 7r-complexes with gold in any of its oxidation states.1-3 Therefore, only a very few stable complexes of this type have been isolated. However, unstable 7r-complexes of olefins with gold compounds are believed to be important intermediates or transient species in gold-catalyzed reactions of unsaturated organic compounds.122-125,131,286-288,307-312... 

Because large quantities of unsaturated organic compounds are obtained by removing hydrogen from saturated hydrocarbons, these processes are also important in production of hydrogen commercially. In one of these processes, hexane is converted to cyclohexane by the reaction... 

Sections I-V of this chapter deal with the syntheses of unsaturated organic compounds playing an essential role in biochemical processes of life. Numerous polyunsaturated compounds have been synthesized in order to elucidate their physiological role, for instance in brain. However, the main impact on permanent searches for new improved methods of synthesis of isotopically labelled dienes and polyenes comes from nuclear medicine and nuclear pharmacy. The deuterium and carbon-13 labelled polyunsaturated compounds are needed as internal standards in mass spectral determinations of very low concentrations of biologically active substances in biological fluids. 

Mercury(II) cyanide Mercury(I) nitrate Mercury(II) nitrate Fluorine, hydrogen cyanide, magnesium, sodium nitrite Phosphorus Acetylene, aromatics, ethanol, hypophosphoric acid, phosphine, unsaturated organic compounds... 

The mechanism of the reaction was first described by Harrod and Chalk [10], It involves the general mechanism of H-X additions to unsaturated organic compounds, starting with an oxidative addition of HX to a zerovalent platinum complex. The process is the same as that of addition of HCN to double bonds (Chapter 11). 

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