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Please login to access the full content or check if you have access via8.1.1.2 Copper-Catalyzed Borylative Ring Closing of Aryl- and Hetaryl-Substituted Allylic Phosphates
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Kubota, K.; Ito, H., Science of Synthesis: Advances in Organoboron Chemistry towards Organic Synthesis, (2019) 1, 228.
A similar procedure is effective for the enantioselective synthesis of aryl- and hetaryl-substituted cyclopropylboronates 5 from Z-allylic phosphates 4 and bis(pinacolato)diboron (2) in good to high yields with excellent enantioselectivities using copper(I) chloride as copper catalyst and a chiral ligand (Scheme 2).[2] The reaction shows excellent diastereoselectivity and good functional-group compatibility. Optimized enantioselectivity is achieved when (R,R)-iPr-DuPhos is used as chiral ligand. When E-allylic phosphates are used as substrates, the products switch from the trans to the cis configuration in the presence of (R,R)-iPr-DuPhos.
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| Me8 | Meee (e) | ee (%) | Meeee (%) | Mee |
|---|---|---|---|---|
| Me | 88 | 88 | 88e | [8] |
| 8-MeMM8M8 | 88 | 88 | 88 | [8] |
| 8-MeM8M8 | 88 | 88 | 88 | [8] |
| 8-Mee | 88 | 88 | 88 | [8] |
| 8-MeM8M8 | 88 | 88 | 88 | [8] |
| 8,8-MeM8M8 | 88 | 88 | 88 | [8] |
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References
| [2] | Meeee, M.; Meeee, M.; Meeeee, M.; Meeeeeee, M.; Mee, M., M. Me. Meee. Mee., (8888) 888, 88888. |
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