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Torregrosa-Chinillach A, Carral-Menoyo A, Gómez-Bengoa E, Chinchilla R. Organocatalytic Enantioselective α-Nitrogenation of α,α-Disubstituted Aldehydes in the Absence of a Solvent. J Org Chem 2022; 87:14507-14513. [PMID: 36283071 PMCID: PMC9639010 DOI: 10.1021/acs.joc.2c01919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A highly efficient enantioselective α-nitrogenation method of α,α-disubstituted aldehydes with azodicarboxylates promoted by a chiral carbamate-monoprotected cyclohexa-1,2-diamine as organocatalyst has been developed. The process was carried out without any solvent, and the corresponding α,α-disubstituted α-nitrogenated aldehydes were obtained with excellent yields and enantioselectivities up to 99% ee. The sustainability of the procedure was established through the calculation of green metrics, such as EcoScale and E-factor. In addition, theoretical calculations have been used to justify the obtained enantioselectivity sense.
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Affiliation(s)
- Alejandro Torregrosa-Chinillach
- Department
of Organic Chemistry and Institute of Organic Synthesis (ISO), University of Alicante, PO Box 99, Alicante 03080, Spain
| | - Asier Carral-Menoyo
- Department
of Organic Chemistry I, University of the
Basque Country UPV/EHU, Manuel Lardizabal 3, Donostia-San Sebastián 20018, Spain
| | - Enrique Gómez-Bengoa
- Department
of Organic Chemistry I, University of the
Basque Country UPV/EHU, Manuel Lardizabal 3, Donostia-San Sebastián 20018, Spain,
| | - Rafael Chinchilla
- Department
of Organic Chemistry and Institute of Organic Synthesis (ISO), University of Alicante, PO Box 99, Alicante 03080, Spain,
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Dean C, Rajkumar S, Roesner S, Carson N, Clarkson GJ, Wills M, Jones M, Shipman M. Readily accessible sp 3-rich cyclic hydrazine frameworks exploiting nitrogen fluxionality. Chem Sci 2020; 11:1636-1642. [PMID: 32206282 PMCID: PMC7069508 DOI: 10.1039/c9sc04849a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/23/2019] [Indexed: 12/12/2022] Open
Abstract
Increased molecular complexity correlates with improved chances of success in the drug development process. Here, a strategy for the creation of sp3-rich, non-planar heterocyclic scaffolds suitable for drug discovery is described that obviates the need to generate multiple stereogenic centers with independent control. Asymmetric transfer hydrogenation using a tethered Ru-catalyst is used to efficiently produce a range of enantiopure cyclic hydrazine building blocks (up to 99% ee). Iterative C-N functionalization at the two nitrogen atoms of these compounds produces novel hydrazine and hydrazide based chemical libraries. Wide chemical diversification is possible through variation in the hydrazine structure, use of different functionalization chemistries and coupling partners, and controlled engagement of each nitrogen of the hydrazine in turn. Principal Moment of Inertia (PMI) analysis of this small hydrazine library reveals excellent shape diversity and three-dimensionality. NMR and crystallographic studies confirm these frameworks prefer to orient their substituents in three-dimensional space under the control of a single stereogenic center through exploitation of the fluxional behavior of the two nitrogen atoms.
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Affiliation(s)
- Conor Dean
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
| | - Sundaram Rajkumar
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
| | - Stefan Roesner
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
| | - Nessa Carson
- AMRI UK, Ltd. , Erl Wood Manor , Windlesham , Surrey GU20 6PH , UK
| | - Guy J Clarkson
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
| | - Martin Wills
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
| | - Matthew Jones
- Eli Lilly & Company Ltd. , Erl Wood Manor , Windlesham , Surrey GU20 6PH , UK
| | - Michael Shipman
- Department of Chemistry , University of Warwick , Gibbet Hill Road , Coventry , CV4 7AL , UK .
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Liu XL, Zhang XL, Xia AB, Guo YJ, Meng CH, Xu DQ. Tryptophan/copper-catalyzed aromatization reaction of chiral cyclohexanones to phenols. Org Biomol Chem 2017; 15:5126-5130. [PMID: 28594034 DOI: 10.1039/c7ob01114h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
By merging organocatalysis with copper catalysis, a highly efficient stereospecific approach for the synthesis of chiral phenols from cyclohexanones has been developed for the first time. The aromatization reaction proceeds through the in situ formation of enone intermediates and further subsequent bromination/dehydrobromination reactions. And a series of functionalized phenol derivatives are obtained in good yields (up to 89%) and good to excellent enantioselectivities (up to 99% ee).
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Affiliation(s)
- Xue-Li Liu
- Catalytic Hydrogenation Research Centre, State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou, 310014, China.
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