A high performance distillation system to remove krypton from xenon was constructed, and a purity level of Kr/Xe = ∼ 3 × 10 −12 was achieved. This development is crucial in facilitating high sensitivity low background experiments such as the search for dark matter in the universe.

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The enantioselective propargylic alkylation of propargylic alcohols bearing an internal alkyne moiety with aldehydes in the presence of a metal salt as the Lewis acid and an optically active secondary amine as the co‐catalyst has been found to give the corresponding propargylic alkylated products in high yields as a mixture of two diastereoisomers with high enantioselectivity.

The enantioselective propargylic alkylation of propargylic alcohols with β-ketoesters in the presence of a thiolate-bridged diruthenium complex and a copper complex as co-catalyst affords the corresponding propargylic alkylated products in excellent yields as a mixture of two diastereoisomers with high enantioselectivity (up to 95% enantiomeric excess (ee)). The findings reported herein not only open up a new type of enantioselective propargylic substitution reaction, but also a new aspect of cooperative catalytic reactions using distinct transition metals to realize a useful transformation that cannot be achieved by a single catalyst.

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