- Palladium-Catalyzed Low Pressure Carbonylation of Allylic Alcohols by Catalytic Anhydride Activation
-
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
-
supporting information
p. 9263 - 9266
(2021/05/27)
-
- PROCESS FOR THE PREPARATION OF UNSATURATED CARBOXYLIC ACIDS BY CARBONYLATION OF ALLYL ALCOHOLS AND THEIR ACYLATION PRODUCTS
-
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.
- -
-
Paragraph 0239-0240
(2020/03/01)
-
- Copper-catalyzed vinylogous aerobic oxidation of unsaturated compounds with air
-
A mild and operationally simple copper-catalyzed vinylogous aerobic oxidation of β,γ- and α,β-unsaturated esters is described. This method features good yields, broad substrate scope, excellent chemo- and regioselectivity, and good functional group tolerance. This method is additionally capable of oxidizing β,γ- and α,β-unsaturated aldehydes, ketones, amides, nitriles, and sulfones. Furthermore, the present catalytic system is suitable for bisvinylogous and trisvinylogous oxidation. Tetramethylguanidine (TMG) was found to be crucial in its role as a base, but we also speculate that it serves as a ligand to copper(II) triflate to produce the active copper(II) catalyst. Mechanistic experiments conducted suggest a plausible reaction pathway via an allylcopper(II) species. Finally, the breadth of scope and power of this methodology are demonstrated through its application to complex natural product substrates.
- Zhang, Hai-Jun,Schuppe, Alexander W.,Pan, Shi-Tao,Chen, Jin-Xiang,Wang, Bo-Ran,Newhouse, Timothy R.,Yin, Liang
-
p. 5300 - 5310
(2018/04/24)
-
- Regioselective Synthesis of β,γ-Unsaturated Acids by the Electrochemical Carboxylation of Allylic Bromides Using a Reactive-metal Anode
-
Electrolysis of γ-mono and disubstituted allylic bromides in the presence of atmospheric pressure of carbon dioxide using a platinum cathode and a magnesium anode gave regioselectively the corresponding γ-mono and disubstituted β,γ-unsaturated carboxylic acids in 34-71percent yields.
- Tokuda, Masao,Kabuki, Takashi,Katoh, Yoshitaka,Suginome, Hiroshi
-
p. 3345 - 3348
(2007/10/02)
-
- LITHIATED CYCLOPROPANONE KETALS
-
The ketene acetal I reacted with dibromocarbene yielding the dibromocyclopropanone ketal II, which was reduced to the monobromide III by treatment with tri-n-butyltin hydride.Reaction of III with n-butyllithium at -78 degC yielded the lithiated cyclopropanone ketal IV, which yielded adducts with acetone, cyclohexanone, cyclohexenone, 3,3,3-trimethoxybutan-2-one, and 3-pentanone.
- Dowd, Paul,Kaufman, Christopher,Kaufman, Paul,Paik, Yi Hyon
-
p. 2279 - 2282
(2007/10/02)
-