Substrate/catalyst ratio

Conversion determined at 30 min reaction time. Experimental conditions Poj = 303.9 kPa substrate/catalyst ratio = 1000 [subst-... 

The substrate/catalyst ratio is 75,000, and one million turnovers are achieved in six hours, giving a product with an ee of 80%. A higher ee can be obtained, at lower substrate/catalyst ratios, but are not actually necessary for this product. This process will be used to produce several thousands tons per annum of (S)-metolachlor, to replace the previously marketed racemic metolaclor. 

Styrenic-siloxane block and graft copolymers, Tg dependence on architecture and molecular weight, 95,95/ Styrenic-siloxane block copolymers, 86 Substrate catalyst ratio, chloromethylation, 18 Sulfonation, instability of sulfonated PPO, improvement, 6 Surface grafting... 

We report here a number of examples of the use of this anchored catalyst for the hydrogenation of different substrates at moderate to high substrate/catalyst ratios along with a direct comparison of these results with those obtained using the homogeneous Wilkinson under the same conditions. Also presented will be some examples of the use of the anchored catalyst in long term continuous reactions. Reaction rates, selectivities and the extent of metal loss will be presented where appropriate. 

Previous studies on the use of Anchored Homogeneous Catalysts (AHC s) have been concerned with studying the effect which different reaction variables had on the activity, selectivity and stability of these catalysts (1-9). These reactions were typically ran at relatively low substrate/catalyst ratios (turnover numbers-TON s), usually between 50 and 100. While these low TON reactions made it possible to obtain a great deal of information concerning the AHC s, in order to establish that these catalysts could be used in commercial applications it was necessary to apply them to reactions at much higher TON S and, also, to make direct comparisons with the corresponding homogeneous catalyst under the same reaction conditions. 

SCR substrate catalyst ratio TOF turnover frequency TON turnover number... 

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