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9. Crystal structures of [µ2-(Ra,Sa,3aR,7aR)-1,3- bis(2,7-dicyclohexylnaphthalen-1-yl)octahydro-1Hbenzo[ d]imidazolidin-2-ylidene]chlorido(µ4-1,5- cyclooctadiene)iridium dichloromethane monosolvate and [µ2-(Ra,Sa,3aR,7aR)-1,3-bis(2,7-dicyclohexylnaphthalen- 1-yl)octahydro-1H-benzo[d]imidazolidin- 2-ylidene]chlorido(µ4-1,5-cyclooctadiene)- iridium.

Author

Moggach, Stephen A., Skelton, Brian W., and Foster, Daven J.

Subjects
IRIDIUM, CHEMICAL formulas, CYCLOOCTADIENE, CRYSTAL structure, DIHEDRAL angles
Abstract

The title compounds, [Ir(C51H64N2)Cl(C8H12)]CH2C2, (I), and [Ir(C51H64N2)- Cl(C8H12)], (II), represent the first two examples of hexahydrobenzoimidazolebased N-heterocyclic carbene (NHC) iridium complexes. The diastereomeric complexes differing only in their axial chirality, which could be separated via column chromatography, show noticeable differences in their 1H NMR spectra. Compound (I) crystallizes in the monoclinic system (P21) with two independent complexes and two half-occupied dichloromethane molecules in the asymmetric unit, while compound (II) crystallizes in the orthorhombic system (P212121) with one complex in the asymmetric unit. The fused five-membered N-heterocycles of NHCs show unusually high backbone torsion angles of 34.1 (5) and 30.9 (5) for (I) and 31.5 (7) for (II), but the Ir--Ccarbene bond lengths of 2.046 (6) and 2.021 (6) A ° for (I) and 2.045 (8) A ° for (II) present typical NHC-- Ir bond lengths. The solvent molecule in the crystal of (I) was found to be highly disordered and its contribution to the scattering was masked using the solventmasking routine smtbx.mask in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst. 42, 339--341]. The solvent contribution is not included in the reported chemical formula and other crystal data. [ABSTRACT FROM AUTHOR]

Published
2020
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13. Accessing Phase-Transfer Catalysts and a Phosphoramidite Ligand viathe Asymmetric Intramolecular Hydroamination Reaction

Author

Foster, Daven, Moggach, Stephen A., and Dorta, Reto

Abstract

Within the last few years, our group has developed the intramolecular, asymmetric hydroamination (HA) reaction to a point where essentially enantiopure products can be obtained. The question then arose as to whether we can apply the reaction in useful ways beyond the synthesis of natural/pharmaceutically relevant products. In the present paper, we incorporate a select few HA products for the production of new chiral phase-transfer catalysts. These species are synthesized in one or two synthetic steps from new spirocyclic HA products and are applied in a classical substitution reaction, showing negligible enantioselectivity. In a second application, we introduce a novel phosphoramidite ligand, obtained by combining BINOL (1,1′-bi-2-naphthol) and an optically pure HA product with phosphorous trichloride. The representative ligand shows high enantioselectivity and activity in the rhodium-catalyzed conjugate addition reaction (Hayashi–Miyaura reaction).

Published
2023
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14. Response to 'Letter to the Editor: Fluoride concentration in SDF commercial products'.

Author

Patel, J, Foster, D, Smirk, M, Turton, BJ, Anthonappa, RP, Patel, Jilen, Foster, Daven, Smirk, Michael, Turton, Bathsheba Jael, Anthonappa, Robert P, Turton, B J, and Anthonappa, R P

Subjects
FLUORIDES, DEIONIZATION of water, SILVER ions, FLUORIDE varnishes, SILVER compounds, QUATERNARY ammonium compounds
Abstract

We would like to direct attention to the materials and methods section of our study which details the lot numbers of the solutions tested, contrary to the suggestion of this not being reported. In addition, the initial testing and feasibility for this study was conducted in June 2018 while definitive laboratory testing of all products was conducted in November 2018. [ABSTRACT FROM AUTHOR]

Published
2021
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15. Crystal structures of [μ 2 -( R a , S a ,3a R ,7a R )-1,3-bis-(2,7-di-cyclo-hexyl-naphthalen-1-yl)octa-hydro-1 H -benzo[ d ]imidazolidin-2-yl-idene]chlorido-(η 4 -1,5-cyclo-octa-diene)iridium di-chloro-methane monosolvate and [μ 2 -( S a , S a ,3a R ,7a R )-1,3-bis-(2,7-di-cyclo-hexyl-naphthalen-1-yl)octa-hydro-1 H -benzo[ d ]imidazolidin-2-yl-idene]chlorido-(η 4 -1,5-cyclo-octa-diene)iridium.

Author

Moggach SA, Skelton BW, and Foster DJ

Abstract

The title compounds, [Ir(C 51 H 64 N 2 )Cl(C 8 H 12 )]·CH 2 Cl 2 , (I), and [Ir(C 51 H 64 N 2 )Cl(C 8 H 12 )], (II), represent the first two examples of hexa-hydro-benzo-imidazole-based N -heterocyclic carbene (NHC) iridium complexes. The diastereomeric complexes differing only in their axial chirality, which could be separated via column chromatography, show noticeable differences in their 1 H NMR spectra. Compound (I) crystallizes in the monoclinic system ( P 2 1 ) with two independent complexes and two half-occupied di-chloro-methane mol-ecules in the asymmetric unit, while compound (II) crystallizes in the ortho-rhom-bic system ( P 2 1 2 1 2 1 ) with one complex in the asymmetric unit. The fused five-membered N -heterocycles of NHCs show unusually high backbone torsion angles of -34.1 (5) and -30.9 (5)° for (I) and -31.5 (7)° for (II), but the Ir-C carbene bond lengths of 2.046 (6) and 2.021 (6) Å for (I) and 2.045 (8) Å for (II) present typical NHC-Ir bond lengths. The solvent mol-ecule in the crystal of (I) was found to be highly disordered and its contribution to the scattering was masked using the solvent-masking routine smtbx.mask in OLEX2 [Dolomanov et al. (2009 ▸). J. Appl. Cryst. 42 , 339-341]. The solvent contribution is not included in the reported chemical formula and other crystal data., (© Moggach et al. 2020.)

Published
2020
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