Ir/Rh-catalyzed hydrogenation of squalene: access to stereoregular squalane
- 1Dipartimento di Scienze Chimiche, Università di Napoli Federico II 80126 Napoli Italy
- 2DPI P.O. Box 902 5600 AX Eindhoven the Netherlands
- 3Department of Chemistry, University of Florida, Center for Catalysis P.O. Box 117200 Gainesville Florida 32611 USA
Abstract
Catalytic stereoselective hydrogenation of unfunctionalized polyenes remains a major challenge because multiple stereogenic centers must be generated in the absence of directing groups. Here we investigate squalene, a flexible hydrocarbon containing six isolated trisubstituted double bonds, as a demanding substrate for assessing stereochemical bias in the complete hydrogenation of an unfunctionalized polyene. Evaluation of Rh- and Ir-based homogeneous catalysts identified one Ir–P,N complex that promotes complete conversion to squalane while inducing a highly non-statistical diastereomeric distribution, reaching up to 90% d.e. The stereochemical outcome was quantified directly by 13C NMR spectroscopy of crude reaction mixtures, without derivatization or chromatographic separation. Buried-volume analysis was used to compare the steric environment of the selective Ir catalyst with representative non-selective systems, providing a qualitative interpretation of the observed behaviour. To our knowledge, this work provides the first catalytic access to stereoregular squalane and establishes a practical NMR-based approach to evaluate stereochemical bias in hydrogenated isoprenoid hydrocarbons.
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BibTeX
@article{iovine2026irrhcatalyzed,
title = {{Ir/Rh-catalyzed hydrogenation of squalene: access to stereoregular squalane}},
author = {Teresa Iovine and Christian Ehm and Umesh I. Kaluarachchige Don and Vincenzo Busico and Adam S. Veige and Roberta Cipullo},
journal = {RSC Advances},
year = {2026},
month = sep,
doi = {10.1039/d6ra05192h},
url = {https://doi.org/10.1039/d6ra05192h},
note = {CC BY 3.0},
}
RIS
TY - JOUR
TI - Ir/Rh-catalyzed hydrogenation of squalene: access to stereoregular squalane
AU - Teresa Iovine
AU - Christian Ehm
AU - Umesh I. Kaluarachchige Don
AU - Vincenzo Busico
AU - Adam S. Veige
AU - Roberta Cipullo
PY - 2026
DA - 2026/09/07
JO - RSC Advances
DO - 10.1039/d6ra05192h
UR - https://doi.org/10.1039/d6ra05192h
AB - Catalytic stereoselective hydrogenation of unfunctionalized polyenes remains a major challenge because multiple stereogenic centers must be generated in the absence of directing groups. Here we investigate squalene, a flexible hydrocarbon containing six isolated trisubstituted double bonds, as a demanding substrate for assessing stereochemical bias in the complete hydrogenation of an unfunctionalized polyene. Evaluation of Rh- and Ir-based homogeneous catalysts identified one Ir–P,N complex that promotes complete conversion to squalane while inducing a highly non-statistical diastereomeric distribution, reaching up to 90% d.e. The stereochemical outcome was quantified directly by 13C NMR spectroscopy of crude reaction mixtures, without derivatization or chromatographic separation. Buried-volume analysis was used to compare the steric environment of the selective Ir catalyst with representative non-selective systems, providing a qualitative interpretation of the observed behaviour. To our knowledge, this work provides the first catalytic access to stereoregular squalane and establishes a practical NMR-based approach to evaluate stereochemical bias in hydrogenated isoprenoid hydrocarbons.
SN - 2046-2069
ER -