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Pérez-Palau M, Sanosa N, Romea P, Urpí F, López R, Gómez-Bengoa E, Font-Bardia M. Stereoselective Alkylation of Chiral Titanium(IV) Enolates with tert-Butyl Peresters. Org Lett 2021; 23:8852-8856. [PMID: 34699246 PMCID: PMC8609576 DOI: 10.1021/acs.orglett.1c03366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Here, we present
a new stereoselective alkylation of titanium(IV)
enolates of chiral N-acyl oxazolidinones with tert-butyl peresters from Cα-branched aliphatic carboxylic
acids, which proceeds through the decarboxylation of the peresters
and the subsequent formation of alkyl radicals to produce the alkylated
adducts with an excellent diastereoselectivity. Theoretical calculations
account for the observed reactivity and the outstanding stereocontrol.
Importantly, the resultant compounds can be easily converted into
ligands for asymmetric and catalytic transformations.
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Affiliation(s)
- Marina Pérez-Palau
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain
| | - Nil Sanosa
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain
| | - Pedro Romea
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain
| | - Fèlix Urpí
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Carrer Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain
| | - Rosa López
- Departamento de Química Orgánica I, Universidad del Pais Vasco, UPV/EHU, Apdo. 1072, 20080 San Sebastián, Spain
| | - Enrique Gómez-Bengoa
- Departamento de Química Orgánica I, Universidad del Pais Vasco, UPV/EHU, Apdo. 1072, 20080 San Sebastián, Spain
| | - Mercè Font-Bardia
- Unitat de Difracció de RX. CCiTUB. Universitat de Barcelona. Carrer Solé i Sabarís 1-3, 08028 Barcelona, Catalonia, Spain
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2
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Prusinowska N, Czapik A, Kwit M. Chiral Triphenylacetic Acid Esters: Residual Stereoisomerism and Solid-State Variability of Molecular Architectures. J Org Chem 2021; 86:6433-6448. [PMID: 33908243 PMCID: PMC8279475 DOI: 10.1021/acs.joc.1c00279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 12/29/2022]
Abstract
We have proven the usability and versatility of chiral triphenylacetic acid esters, compounds of high structural diversity, as chirality-sensing stereodynamic probes and as molecular tectons in crystal engineering. The low energy barrier to stereoisomer interconversion has been exploited to sense the chirality of an alkyl substituent in the esters. The structural information are cascaded from the permanently chiral alcohol (inducer) to the stereodynamic chromophoric probe through cooperative interactions. The ECD spectra of triphenylacetic acid esters are highly sensitive to very small structural differences in the inducer core. The tendencies to maximize the C-H···O hydrogen bonds, van der Waals interactions, and London dispersion forces determine the way of packing molecules in the crystal lattice. The phenyl embraces of trityl groups allowed, to some extent, the control of molecular organization in the crystal. However, the spectrum of possible molecular arrangements is very broad and depends on the type of substituent, the optical purity of the sample, and the presence of a second trityl group in the proximity. Racemates crystallize as the solid solution of enantiomers, where the trityl group acts as a protecting group for the stereogenic center. Therefore, the absolute configuration of the inducer is irrelevant to the packing mode of molecules in the crystal.
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Affiliation(s)
- Natalia Prusinowska
- Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61 614 Poznań, Poland
- Centre
for Advanced Technologies, Adam Mickiewicz
University, Uniwersytetu
Poznańskiego 10, 61 614 Poznań, Poland
| | - Agnieszka Czapik
- Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61 614 Poznań, Poland
| | - Marcin Kwit
- Faculty
of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego
8, 61 614 Poznań, Poland
- Centre
for Advanced Technologies, Adam Mickiewicz
University, Uniwersytetu
Poznańskiego 10, 61 614 Poznań, Poland
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3
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Stasiak B, Czapik A, Kwit M. Dynamic Induction of Optical Activity in Triarylmethanols and Their Carbocations. J Org Chem 2021; 86:643-656. [PMID: 33348985 PMCID: PMC7872417 DOI: 10.1021/acs.joc.0c02289] [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: 11/30/2022]
Abstract
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A series of artificial triarylmethanols
has been synthesized and
studied toward the possibility of exhibiting an induced optical activity.
The observed chiroptical response of these compounds resulted from
the chiral conformation of a triarylmethyl core. The chirality induction
from a permanent chirality element to the liable triarylmethyl core
proceeds as a cooperative and cascade process. The OH···O(R)
and/or (H)O···HorthoC hydrogen
bond formation along with the C–H···π
interactions seem to be the most important factors that control efficiency
of the chirality induction. The position of chiral and methoxy electron-donating
groups within a trityl skeleton affects the amplitude of observed
Cotton effects and stability of the trityl carbocations. In the neutral
environment, the most intense Cotton effects are observed for ortho-substituted derivatives, which undergo a rapid decomposition
associated with the complete decay of ECD signals upon acidification.
From all of the in situ generated stable carbocations, only two exhibit
intense Cotton effects in the low energy region at around 450 nm.
The formation of carbocations is reversible; after alkalization, the
ions return to the original neutral forms. Unlike most triarylmethyl
derivatives known so far, in the crystal, the triarylmethanol, para-substituted with the chiral moiety, shows a propensity
for a solid-state sorting phenomenon.
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Affiliation(s)
- Bartosz Stasiak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznań, Poland
| | - Agnieszka Czapik
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznań, Poland
| | - Marcin Kwit
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61 614 Poznań, Poland.,Centre for Advanced Technologies, Adam Mickiewicz University, Uniwersytetu Poznanskiego 10, 61 614 Poznań, Poland
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Romo JM, Romea P, Urpí F. Direct anti
Glycolate Aldol Reaction of Protected Chiral N
-Hydroxyacetyl Thiazolidinethiones with Acetals Catalyzed by a Nickel(II) Complex. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Juan Manuel Romo
- Department of Inorganic and Organic Chemistry; Section of Organic Chemistry, and Institute of Biomedicine (IBUB); University of Barcelona; Carrer Martí I Franqués 1-11 08028 Barcelona Catalonia Spain
| | - Pedro Romea
- Department of Inorganic and Organic Chemistry; Section of Organic Chemistry, and Institute of Biomedicine (IBUB); University of Barcelona; Carrer Martí I Franqués 1-11 08028 Barcelona Catalonia Spain
| | - Fèlix Urpí
- Department of Inorganic and Organic Chemistry; Section of Organic Chemistry, and Institute of Biomedicine (IBUB); University of Barcelona; Carrer Martí I Franqués 1-11 08028 Barcelona Catalonia Spain
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5
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Kennington SCD, Taylor AJ, Romea P, Urpí F, Aullón G, Font-Bardia M, Ferré L, Rodrigalvarez J. Direct and Asymmetric Nickel(II)-Catalyzed Construction of Carbon-Carbon Bonds from N-Acyl Thiazinanethiones. Org Lett 2019; 21:305-309. [PMID: 30582705 DOI: 10.1021/acs.orglett.8b03757] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A wide array of new N-acyl thiazinanethiones are employed in a number of direct and enantioselective carbon-carbon-bond-forming reactions catalyzed by nickel(II) complexes. The electrophilic species are mostly prepared in situ from ortho esters, methyl ethers, acetals, and ketals, which makes the overall process highly efficient and experimentally straightforward. Theoretical calculations indicate that the reactions proceed through an open transition state in a SN1-like mechanism. The utility of this novel procedure has been demonstrated by the asymmetric preparation of synthetically useful intermediates and the total synthesis of peperomin D.
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Affiliation(s)
- Stuart C D Kennington
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Adam J Taylor
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Pedro Romea
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Fèlix Urpí
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Gabriel Aullón
- Department of Inorganic and Organic Chemistry, Section of Inorganic Chemistry , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Mercè Font-Bardia
- Unitat de Difracció de RX, CCiTUB, Universitat de Barcelona , Carrer Solé i Sabarís 1-3 , 08028 Barcelona , Catalonia , Spain
| | - Laura Ferré
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
| | - Jesus Rodrigalvarez
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, and Institute of Biomedicine (IBUB) , University of Barcelona , Carrer Martí i Franqués 1-11 , 08028 Barcelona , Catalonia , Spain
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