Announcements

1. Make sure that you make progress on your formal report as well in terms of literature search and writing the parts that you completed already in the lab.

2. The next will be administered on Monday October 16, 2006 at 12 pm. The material covered will mainly include the ligand (step 4) and the resolution step (step 1). Please make sure that you show up on time.

3. The draft version of paper is due on 10-27-2006 at 5 pm. The draft version is worth 15 points, the final paper 45 points. For more information what the draft is supposed to contain see here. Late submission will receive less credit. The more of your work you submit here, the more feedback you will get, which will beneficial for the final version. We will try to return the reports by Monday.

ATTN: Answers to the below questions are due at the start of your lab period; these answers should be part of your pre-lab write-up.

1. Referring to the synthesis and characterization of the Jacobsen catalyst, answer the following questions.

a. The procedure asks to crush up the manganese acetate. Explain.

b. The progress of the reaction is monitored by TLC. Which solvent is used? Sketch a plate showing an incomplete reaction.

c. After drying the solution, heptane is added to the organic layer and then the volume of the mixture reduced. Rationalize this step. How does the student know that he reduced the volume enough?

d. A student plans to acquire the UV-Vis spectrum for the catalyst in the range from 200-700 nm. Determine the appropriate concentration. Which solvent and which cuvette should be used?

e. Why do we not determine the optical rotation for the catalyst?

2. Referring to the design of the catalyst, anser the following questions.

a. Manganese is used as metal center for the catalyst. Give two alternative metals that could be used as well.

b. One of the key intermediates in the catalytic cycle of the Jacobsen catalyst is the formation of an Mn=O species. Why is this intermediate important?

c. What is the function of the tert.-butyl groups in the catalyst?

d. In which way does the presence of methoxy groups influence the reactivity and selectivity of the catalyst?