- Gold(I)-catalyzed decarboxylation of propargyl carbonates: Reactivity reversal of the gold catalyst from π-Lewis acidity to σ-Lewis acidity
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A cationic gold(I)-catalyzed decarboxylative etherification of propargyl carbonates to selectively produce propargyl ethers is reported. In the reaction the gold(I) catalyst shows a distinct σ-Lewis acidity rather than the commonly observed π-Lewis acidity, and thus catalyzes the decarboxylation of a variety of propargyl carbonates to give the corresponding propargyl ethers with high selectivity. This reaction represents a rare example of the tunable reactivity of cationic gold(I) complexes between σ-Lewis acidity and π-Lewis acidity.
- Shen, Ruwei,Yang, Jianjun,Zhu, Shugao,Chen, Chao,Wu, Luling
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supporting information
p. 1259 - 1269
(2015/04/22)
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- Ester manufacturing method (by machine translation)
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PROBLEM TO BE SOLVED: To produce an ester compound by transesterification using an inexpensive and low toxic inorganic compound. SOLUTION: Transesterification of an ester compound and an alcohol compound is carried out under the presence of lanthanum nitrate (for example, lanthanum nitrate hexahydrate) and a phosphine compound (for example, tri-n-octylphosphine), thereby obtaining the ester product. For example, transesterification of dimethyl carbonate and benzyl alcohol is carried out under the presence of 1 mol% of lanthanum nitrate hexahydrate, and 2 mol% of tri-n-octylphosphine, thereby obtaining benzyl methylcarbonate at a yield of >99%. COPYRIGHT: (C)2012,JPO&INPIT
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Paragraph 0035; 0037; 0038
(2017/02/17)
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- Copper-catalyzed regiodivergent silacarboxylation of allenes with carbon dioxide and a silylborane
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A regiodivergent silacarboxylation of allenes under a CO2 atmosphere with PhMe2Si-B(pin) as a silicon source in the presence of a copper catalyst at 70 °C has been developed. The regioselectivity of the reaction is successfully rever
- Tani, Yosuke,Fujihara, Tetsuaki,Terao, Jun,Tsuji, Yasushi
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supporting information
p. 17706 - 17709
(2015/02/19)
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- In situ generated "lanthanum(iii) nitrate alkoxide" as a highly active and nearly neutral transesterification catalyst
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In situ generated lanthanum(iii) nitrate alkoxide is a highly active and nearly neutral transesterification catalyst, which can promote non-epimerized transesterification of α-substituted chiral carboxylic esters under reflux conditions.
- Hatano, Manabu,Kamiya, Sho,Ishihara, Kazuaki
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supporting information
p. 9465 - 9467
(2012/10/29)
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- Lanthanum(III) isopropoxide catalyzed chemoselective transesterification of dimethyl carbonate and methyl carbamates
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A practical transesterification of less reactive dimethyl carbonate and much less reactive methyl carbamates with primary (1°), secondary (2°), and tertiary (3°) alcohols was established with the use of a lanthanum(III) complex, which was prepared in situ from lanthanum (III) isopropoxide (3 mol %) and 2-(2-methoxyethoxy)ethanol (6 mol %). In particular, corresponding carbonates and carbamates obtained were of synthetic utility from the viewpoint of the selective protection and/or deprotection of 1°-, 2°-, and 3°-alcohols.
- Hatano, Manabu,Kamiya, Sho,Moriyama, Katsuhiko,Ishihara, Kazuaki
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supporting information; experimental part
p. 430 - 433
(2011/04/15)
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- Cycloalkyl carbonates
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Carbonic acid esters of the formula STR1 wherein R1 is a member having from 8 to 12 carbon atoms selected from the group consisting of alkylcyclohexyl, alkenylcyclohexyl, alkynylcyclohexyl and cycloalkyl, and R2 is a member selected from the group consisting of alkyl having from 1 to 5 carbon atoms, alkenyl having from 2 to 5 carbon atoms and alkynyl having from 2 to 5 carbon atoms, which compounds have pleasing and persistent scents, as well as processes for producing them and perfume compositions containing them.
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