Linear addition reactions

Examples of linear addition reactions that form C-O, C-S, C-N, C-P, C-C, and C-Si bonds are reviewed. Only a few of the growing number of linear additions that form a carbon-transition metal bond are included... 

Linear Addition Reactions toCsC Bonds 2.1.1.5.1. Radical Addition of Perhaloalkanes to Various Alkynes Simple Alkynes... 

Polyethylene, a linear polymer, is made by an addition reaction. It is started with an initiator, such as FIjOj, which gives free, and very reactive —OFI radicals. One of these breaks the double-bond of an ethylene molecule, C2FI4, when it is heated under pressure, to give... 

The borohydride reduction rate data are paralleled by the rate data for many other carbonyl addition reactions. In fact, for a series of ketones, most of which are cyclic, a linear free-energy correlation of the form... 

This trend is revealed, for example, by the rates of Diels-Alder addition reactions of anthracene, naphthacene, and pentacene, in which three, four, and five rings, respectively are linearly fused. The rate data are shown in Table 9.3. The same trend can be seen in the activation energy and the resonance energy gained when cycloreversion of the adducts 9-12 yields the aromatic compoimd, as shown in Scheme 9.3. 

Ru(NO)2(PPh3)2 has a similar electronic structure to the [M(NO)2(PPh3)2]+ (M = Rh, Ir) ions and like them has a pseudo tetrahedral structure with linear Ru-N—O [126]. It also resembles them in its oxidative addition reactions (Figure 1.47). 

The mechanism for the formation of complex hydrocarbons through fullerenes is loosely taken from Helden et al.119 and Hunter et al.,120 and is depicted in Figure 2. As in the work of Thaddeus,117 linear carbon clusters grow via carbon insertion and radiative association reactions, although in this case a large number of additional reactions involving neutral atoms such as C, O, and H and neutral molecules such as H2 are also included. Reactions with H and H2 serve to produce... 

Here the alkene and pyridine will compete for the carbene at a constant concentration of pyridine the observed pseudo first order rate constant for ylide formation will increase with increasing alkene concentration. A plot of kobs vs. [alkene] will be linear with a slope of kad, which is the rate constant for the carbene/alkene addition reaction affording cyclopropane 5 (Scheme 1). 

The second intermediate s identity has been debated since the mid-1980s. In 1984, Liu and Tomioka suggested that it was a carbene-alkenc complex (CAC).17 Similar complexes had been previously postulated to rationalize the negative activation energies observed in certain carbene-alkene addition reactions.11,30 A second intermediate is not limited to the CAC, however. In fact any other intermediate, in addition to the carbene, will satisfy the kinetic observations i.e., that a correlation of addn/rearr vs. [alkene] is curved, whereas the double reciprocal plot is linear.31 Proposed second intermediates include the CAC,17 an excited carbene,31 a diazo compound,23 or an excited diazirine.22,26 We will consider the last three proposals collectively below as rearrangements in the excited state (RIES). 

We will generally not be concerned here with chemical reactions, so the Ri term can be omitted, in which case the subscript i denoting species is no longer required. In addition, for the turbulent flows of interest the molecular diffusion term in Eq. (2.1) may be neglected. [Although for the spatial scales of interest to us the molecular diffusion term may be neglected, molecular and turbulent diffusion are not independent, linearly additive, physical processes (Saffman, I960).] As a result of the above two simplifications, Eq. (2.1) becomes... 

Mark-Houwink equation phys chem The relationship between intrinsic viscosity and molecular weight for homogeneous linear polymers. mark hau.wigk l.kwa-zhan Markovnikoff s rule org chem in an addition reaction, the additive molecule RH adds as H and R, with the R going to the carbon atom with the lesser number of hydrogen atoms bonded to it. mar kov-ns.kofs, riil ... 

The linear telomerization reaction of dienes was one of the very first processes catalyzed by water soluble phosphine complexes in aqueous media [7,8]. The reaction itself is the dimerization of a diene coupled with a simultaneous nucleophilic addition of HX (water, alcohols, amines, carboxylic acids, active methylene compounds, etc.) (Scheme 7.3). It is catalyzed by nickel- and palladium complexes of which palladium catalysts are substantially more active. In organic solutions [Pd(OAc)2] + PPhs gives the simplest catalyst combination and Ni/IPPTS and Pd/TPPTS were suggested for mnning the telomerizations in aqueous/organic biphasic systems [7]. An aqueous solvent would seem a straightforward choice for telomerization of dienes with water (the so-called hydrodimerization). In fact, the possibility of separation of the products and the catalyst without a need for distillation is a more important reason in this case, too. 

---