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We report herein the synthesis of primary and secondary β-chalcogen amines through the regioselective ring-opening reaction of non-activated 2-oxazolidinones promoted by in situ generated chalcogenolate anions. The developed one-step protocol enabled the preparation of β-selenoamines, β-telluroamines and β-thioamines with appreciable structural diversity and in yields of up to 95%.
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Asymmetric synthesis of an atropisomeric β-carboline via regioselective intermolecular Rh(I)-catalyzed [2 + 2 + 2] cyclotrimerization
The rational design of atropisomeric small molecules is becoming increasingly common in chemical synthesis as a result of the unique advantages this property provides in drug discovery, asymmetric catalysis, and chiroptical activity. In this study, we designed a synthesis of a configurationally stable β-carboline in six steps. Our synthesis made use of an innovative Grignard addition/elimination reaction that formed an yne-ynamide precursor that then reacted with ethyl cyanoformate in a rhodium(I)-catalyzed [2 + 2 + 2] cyclotrimerization reaction to give the atropisomeric β-carboline in excellent yield, good enantioselectivity, and excellent regioselectivity. Extensive optimization of this transformation is described. Racemization kinetics experiments were also conducted on the individual atropisomers and their absolute configurations were determined by circular dichroism.
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- Award ID(s):
- 1955132
- PAR ID:
- 10553675
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Tetrahedron Letters
- Volume:
- 146
- Issue:
- C
- ISSN:
- 0040-4039
- Page Range / eLocation ID:
- 155187
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.tetlet.2024.155187
