Chemical readions

The classical kinetic resolution of racemic substrate precursors allows only access to a theoretical 50% yield of the chiral ladone product, while the antipodal starting material remains unchanged in enantiomerically pure form. The regioseledivity for the enzymatic oxidation correlates to the chemical readion with preferred and exclusive migration of the more nucleophilic center (usually the higher substituted a-carbon). The majority of cydoketone converting BVMOs (in particular CHMOAdneto)... 

The salt Na2Si03, known as water-glass, is used instead of orthosilidc add. It is stored in basic media. To perform sol-gel processes, hydrochloric add is added. When the pH drops below 7, a transition into a gel state is observed. The chemical readion can be represented as follows ... 

S. Kobayashi, T. Busujima, S. Nagayama, Scandium Triflate-Catalyzed Strecker-Type Readions of Aldehydes, Amines, and Tributyltin Cyanide in Both Organic and Aqueous Solutions. Achievement of Com-plde Recovery of the Tin Compounds toward Environmentally Friendly Chemical Processes Chem. Commun 1998, 981-982. 

Cation-exchange resins are used as catalysts in the produdion of MTBE (methyl tertiary-butyl ether, 2-methoxy-2-methylpropane) and various other oxygenates and, lately, also in the dimerization of isobutene [30]. Other commercial applications of the cation-exchange resins indude dehydration of alcohols, alkylation of phenols, condensation readions, alkene hydration, purification of phenol, ester hydrolysis and other reactions [31]. The major producers of ion-exchange resins are Sybron Chemicals Incorporated [32] (Lewatit resins), Dow Chemical Company [33] (DOWEX resins), Purolite [28] (Purolite resins), and Rohm and Haas Company [27] (Amberlyst resins). 

If we run the same readion starting from a 200 1 mole/mole mixture of A and B, the change in [A] will never be more than 0.5%, because even at full conversion there will still be 199 equivalents of A left. This means that [A] = [A]0, giving a pseudo first-order readion profile that depends only on [B]. In the corresponding rate equation (Eq. (2.57)), the pseudo first-order constant k = k[A]0. Pseudo order conditions are very useful for isolating the contribution of a chemical species to the rate-determining step. 

Palladium-catalyzed cross-coupling readions are a cornerstone of modern organic synthesis. Combining microwave irradiation and solid-phase synthesis with these chemical transformations is therefore of great interest. One of the first publica-... 

Hagiwara, H. N. Komatsubara H. Ono T. Okabe T. Hoshi T. Suzuki M. Ando and M. Kato (2001). "Diethylamino(trimethyl)silane-mediated direct 1,4-addition of naked aldehydes to electron-defident olefins." Journal of the Chemical Society-Perkin Transactions 1, No.3, (Jan 11,2001), pp. 316-322, ISSN 1472-7781 Hagiwara, H. T. Okabe K Hakoda T. Hoshi H. Ono V. P. Kamat T. Suzuki and M. Ando (2001). "Catalytic enamine readion an expedient 1,4-conjugate addition of naked... 

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