- Palladium-Catalyzed Low Pressure Carbonylation of Allylic Alcohols by Catalytic Anhydride Activation
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A direct carbonylation of allylic alcohols has been realized for the first time with high catalyst activity at low pressure of CO (10 bar). The procedure is described in detail for the carbonylation of E-nerolidol, an important step in a new BASF-route to (?)-ambrox. Key to high activities in the allylic alcohol carbonylation is the finding that catalytic amounts of carboxylic anhydride activate the substrate and are constantly regenerated with carbon monoxide under the reaction conditions. The identified reaction conditions are transferrable to other substrates as well.
- Schelwies, Mathias,Paciello, Rocco,Pelzer, Ralf,Siegel, Wolfgang,Breuer, Michael
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supporting information
p. 9263 - 9266
(2021/05/27)
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- Enantioselective Alkylamination of Unactivated Alkenes under Copper Catalysis
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An enantioselective addition reaction of various alkyl groups to unactivated internal alkenes under Cu catalysis has been developed. The reaction uses amide-linked aminoquinoline as the directing group, 4-alkyl Hantzsch esters as the donor of alkyl radicals, and rarely used biaryl diphosphine oxide as a chiral ligand. β-lactams featuring two contiguous stereocenters at Cβ and the β substituent can be obtained in good yield with excellent enantioselectivity. Mechanistic studies indicate that a nucleophilic addition of the alkyl radical to CuII-coordinated alkene is the enantio-determining step.
- Bai, Zibo,Zhang, Heng,Wang, Hao,Yu, Hanrui,Chen, Gong,He, Gang
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supporting information
p. 1195 - 1202
(2021/02/05)
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- PROCESS FOR THE PREPARATION OF UNSATURATED CARBOXYLIC ACIDS BY CARBONYLATION OF ALLYL ALCOHOLS AND THEIR ACYLATION PRODUCTS
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The present invention relates to a process for carbonylating allyl alcohols at low temperature, low pressure and/or low catalyst loading. In an alternative embodiment, an acylation product of the allyl alcohol is used for the carbonylation. The present invention likewise relates to the preparation of conversion products of these carbonylation products and specifically of (?)-ambrox.
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Paragraph 0231-0232
(2020/03/01)
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- Structure-Odor Relationships of (Z)-3-Alken-1-ols, (Z)-3-Alkenals, and (Z)-3-Alkenoic Acids
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(Z)-3-Unsaturated volatile acids, alcohols, and aldehydes are commonly found in foods and other natural sources, playing a vital role in the attractiveness of foods but also as compounds with chemocommunicative function in entomology. However, a systematic investigation of their smell properties, especially regarding humans, has not been carried out until today. To close this gap, the odor thresholds in air and odor qualities of homologous series of (Z)-3-alken-1-ols, (Z)-3-alkenals, and (Z)-3-alkenoic acids were determined by gas chromatography-olfactometry. It was found that the odor qualities in the series of the (Z)-3-alken-1-ols and (Z)-3-alkenals changed, with increasing chain length, from grassy, green to an overall fatty and citrus-like, soapy character. On the other hand, the odor qualities of the (Z)-3-alkenoic acids changed successively from cheesy, sweaty via plastic-like, to waxy in their homologous series. With regard to their odor potencies, the lowest thresholds in air were found for (Z)-3-hexenal, (Z)-3-octenoic acid, and (Z)-3-octenal.
- Lorber, Katja,Zeh, Gina,Regler, Johanna,Buettner, Andrea
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p. 2334 - 2343
(2018/03/21)
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- Enantiodivergent and γ-selective asymmetric allylic amination
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Double agent: The title reaction using the guanidine catalyst 1 can deliver both enantiomers of the product with excellent enantioselectivity by judicious choice of the double bond geometry of the the β,γ-unsaturated carbonyl compound. Computational studies reveal the possible origin of the inversed enantioselectivity, and the potential for enantiodivergent synthesis chiral amine-containing substrates is attractive. Copyright
- Wang, Jianmin,Chen, Jie,Kee, Choon Wee,Tan, Choon-Hong
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supporting information; experimental part
p. 2382 - 2386
(2012/05/19)
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