A versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid‐catalyzed formal [3+2]‐ and [3+2+2]‐cycloadditions of ketenes with azomethine imines is described. The methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (R=alkyl, OAc). The products were formed in good to excellent yields (71–99 % for 24 examples, 39 examples in all), with good to excellent diastereoselectivity in many cases (dr 3 : 1 to 27 : 1 for 22 examples), and with excellent enantioselectivity for most examples (≥93 %
Catalytic hydrogenolysis of the
- NSF-PAR ID:
- 10238200
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- European Journal of Organic Chemistry
- Volume:
- 2020
- Issue:
- 35
- ISSN:
- 1434-193X
- Page Range / eLocation ID:
- p. 5752-5764
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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