1
|
Vila J, Solà M, Achard T, Bellemin-Laponnaz S, Pla-Quintana A, Roglans A. Rh(I) Complexes with Hemilabile Thioether-Functionalized NHC Ligands as Catalysts for [2 + 2 + 2] Cycloaddition of 1,5-Bisallenes and Alkynes. ACS Catal 2023; 13:3201-3210. [PMID: 36910871 PMCID: PMC9990073 DOI: 10.1021/acscatal.2c05790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/12/2023] [Indexed: 02/19/2023]
Abstract
The [2 + 2 + 2] cycloaddition of 1,5-bisallenes and alkynes under the catalysis of Rh(I) with hemilabile thioether-functionalized N-heterocyclic carbene ligands is described. This protocol effectively provides an entry to different trans-5,6-fused bicyclic systems with two exocyclic double bonds in the cyclohexene ring. The process is totally chemoselective with the two internal double bonds of the 1,5-bisallenes being involved in the cycloaddition. The complete mechanism of this transformation as well as the preference for the trans-fusion over the cis-fusion has been rationalized by density functional theory calculations. The reaction follows a typical [2 + 2 + 2] cycloaddition mechanism. The oxidative addition takes place between the alkyne and one of the allenes and it is when the second allene is inserted into the rhodacyclopentene that the trans-fusion is generated. Remarkably, the hemilabile character of the sulfur atom in the N-heterocyclic carbene ligand modulates the electron density in key intermediates, facilitating the overall transformation.
Collapse
Affiliation(s)
- Jordi Vila
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/Maria Aurèlia Capmany, 69, Girona, 17003 Catalunya, Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/Maria Aurèlia Capmany, 69, Girona, 17003 Catalunya, Spain
| | - Thierry Achard
- Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS-Université de Strasbourg, UMR7504, 23 Rue du Loess BP 43, 67034 Strasbourg, France
| | - Stéphane Bellemin-Laponnaz
- Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS-Université de Strasbourg, UMR7504, 23 Rue du Loess BP 43, 67034 Strasbourg, France
| | - Anna Pla-Quintana
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/Maria Aurèlia Capmany, 69, Girona, 17003 Catalunya, Spain
| | - Anna Roglans
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/Maria Aurèlia Capmany, 69, Girona, 17003 Catalunya, Spain
| |
Collapse
|
2
|
Vila J, Solà M, Pla-Quintana A, Roglans A. Highly Selective Synthesis of Seven-Membered Azaspiro Compounds by a Rh(I)-Catalyzed Cycloisomerization/Diels-Alder Cascade of 1,5-Bisallenes. J Org Chem 2022; 87:5279-5286. [PMID: 35324177 PMCID: PMC9016767 DOI: 10.1021/acs.joc.2c00065] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
The synthesis of
spiro compounds featuring seven- and six-membered
rings in the spirobicyclic motif is successfully achieved through
a cascade process encompassing a rhodium(I)-catalyzed cycloisomerization
followed by a highly selective Diels–Alder homodimerization.
The scope of the reaction is analyzed based on a series of synthetic
substrates, and control experiments and DFT calculations led us to
justify the exquisite degree of selectivity observed.
Collapse
Affiliation(s)
- Jordi Vila
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/ Maria Aurèlia Capmany, 69, Girona 17003, Catalonia, Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/ Maria Aurèlia Capmany, 69, Girona 17003, Catalonia, Spain
| | - Anna Pla-Quintana
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/ Maria Aurèlia Capmany, 69, Girona 17003, Catalonia, Spain
| | - Anna Roglans
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Facultat de Ciències, Universitat de Girona (UdG), C/ Maria Aurèlia Capmany, 69, Girona 17003, Catalonia, Spain
| |
Collapse
|