Read and answer the following questions?
- Summarize, in your own words, what the Ess and Roush Groups studied in this paper.
- In a hydroboration reaction, which product (E or Z) is expected to form?
- Why is this product expected?
- Draw the two possible products that can form (Scheme 1).
- Give the reference for the paper where it was shown that (Z)-crotyl-10-TMS-9-borabicyclo[3.3.2]decanes are more thermodynamically stable.
- Give the specific reaction being studied.
- What led the group to study allene hydroboration?
- How are they studying this reaction (i.e. what methods are they using)?
- Which product, Z-3 or E-3, requires less energy to form?
- Give one reason this product is observed.
- What is the structure of 9-BBN?
- What does the phrase “Z-E hydroboration selectivity†mean?
- Describe the TS that converts Z-3 into E-3.
- What does it mean to be “kinetically favored�
- What causes the increase in barrier for the rearrangement of Z-7?
- In Scheme 4a, what is the most thermodynamically stable product Z-5 or E-5?
- In Scheme 4a, what is the most thermodynamically stable product Z-7 or E-7?
- In Scheme 4a, which is the kinetically favored product, Z-5 or E-5?
- In Scheme 4a, which is the kinetically favored product, Z-7 or E-7?
- Label the energy profile below for the reaction of 1a and 2b.
- What causes the large barriers for TS-Z9 and TS-E9?
- Does the Si atom of the TMS group affect the barrier of TS-Z7?
- If yes, how does it affect the barrier. If no, why does it not affect the barrier?
- How many boat/chair conformations of the borabicyclo auxiliary exist?
What do the authors conclude the cause of kinetic control to be?
