Abstract The development of a platinum‐catalyzed desaturation of cyclic ketones to their conjugated α,β‐unsaturated counterparts is reported in this full article. A unique diene‐platinum complex was identified to be an efficient catalyst, which enables direct metal‐enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including those sensitive to acids, bases/nucleophiles, or palladium species, are tolerated, which represents a distinct feature from other known desaturation methods. Mechanistically, this platinum catalysis exhibits a fast and reversible α‐deprotonation followed by a rate‐determining β‐hydrogen elimination process, which is different from the prior Pd‐catalyzed desaturation method. Promising preliminary enantioselective desaturation using a chiral‐diene‐platinum complex has also been obtained.
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Thermally accelerated curing of platinum-catalyzed elastomers
Silicone elastomers exhibit extraordinary compliance, positioning them as a material of choice for soft robots and devices. To accelerate curing times of platinum-catalyzed silicone elastomers, researchers have employed elevated temperatures; however, knowledge of the requisite duration for curing at a given temperature has remained limited to specific elastomers and has relied primarily on empirical trends. This work presents an analytical model based on an Arrhenius framework coupled with data from thermo-rheological experiments to provide guidelines for suitable curing conditions for commercially available addition-cured platinum-catalyzed silicone elastomers. The curing reaction exhibits self-similarity upon normalizing to a dimensionless reaction coordinate, allowing quantification of the extent of curing under arbitrary time-varying thermal conditions. Mechanical testing revealed no significant changes in properties or performance as a result of thermally accelerated curing. With this framework, higher throughput of elastomeric components can be achieved, and the design space for elastomer-based manufacturing can be developed beyond conventional casting.
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- Award ID(s):
- 2144809
- PAR ID:
- 10536177
- Publisher / Repository:
- Cell Press
- Date Published:
- Journal Name:
- Cell Reports Physical Science
- Volume:
- 5
- Issue:
- 3
- ISSN:
- 2666-3864
- Page Range / eLocation ID:
- 101849
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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