CuI/amino acid catalysis in coupling and cyclization of β-bromo-α,β-unsaturated carboxylic acids with terminal alkynes leading to alkylidenefuranones

2013 ◽  
Vol 27 (5) ◽  
pp. 277-282 ◽  
Author(s):  
Son Long Ho ◽  
Chan Sik Cho ◽  
Heung-Jin Choi ◽  
Ho-Sang Sohn
Keyword(s):  
Amino Acid ◽  
Carboxylic Acids ◽  
Acid Catalysis ◽  
Terminal Alkynes ◽  
Unsaturated Carboxylic Acids

Scalable Synthesis of a Chiral Selenium π-Acid Catalyst and Its Use in Enantioselective Iminolactonization of β,γ-Unsaturated Amides

Synlett ◽  
2019 ◽  
Vol 30 (14) ◽  
pp. 1679-1682 ◽  
Author(s):  
Yuta Otsuka ◽  
Yuto Shimazaki ◽  
Hitoshi Nagaoka ◽  
Keiji Maruoka ◽  
Takuya Hashimoto
Keyword(s):  
Carboxylic Acids ◽  
Asymmetric Catalysis ◽  
Acid Catalysis ◽  
Acid Catalyst ◽  
Oxidative Cyclization ◽  
Unsaturated Carboxylic Acids ◽  
Long Time ◽  
Scalable Synthesis ◽  
Enantioselective Catalysts

Chiral selenium π-acid catalysis has for a long time been lagging behind other areas of asymmetric catalysis due to a lack of highly enantioselective catalysts. In this regard, we recently developed the first chiral selenium π-acid catalyst which performs the oxidative cyclization of β,γ-unsaturated carboxylic acids with high enantioselectivities. We report herein our improved synthesis of this chiral selenium catalyst, which allows access to a large quantity of the catalyst as the diselenide. In addition, the catalyst is tested in the oxidative cyclization of N-methoxy β,γ-unsaturated amides to give iminolactones with high enantioselectivities.

Co-catalysis over a tri-functional ligand modified Pd-catalyst for hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids

2019 ◽  
Vol 21 (19) ◽  
pp. 5336-5344 ◽  
Author(s):  
Da Yang ◽  
Huan Liu ◽  
Lei Liu ◽  
Wen-Di Guo ◽  
Yong Lu ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Pd Catalyst ◽  
Terminal Alkynes ◽  
Unsaturated Carboxylic Acids ◽  
Sulfonate Anion

An amphiphilic tri-functional ligand (L1) containing a phosphonium cation, a phosphino-fragment and a hydrophilic sulfonate anion enabled Pd(OAc)2 to co-catalyze hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids.

Perturbation theory of substituent effect. Importance of the field effect in transmission of the substituent effect

1980 ◽  
Vol 45 (6) ◽  
pp. 1655-1661 ◽  
Author(s):  
Robert Ponec
Keyword(s):  
Perturbation Theory ◽  
Carboxylic Acids ◽  
Quantum Chemical ◽  
Substituent Effect ◽  
Field Effect ◽  
Adequate Description ◽  
Meta Position ◽  
Unsaturated Carboxylic Acids

Various quantum chemical approaches to the problem of transmission of the substituent effect were compared. It was shown that inclusion of the electronic repulsion (field effect) was necessary to give a true picture of differences in ρ constants for reactions of the cis and trans isomers of substituted unsaturated carboxylic acids; the same holds for an adequate description of transmission of the substituent effect from the meta position on a given skeleton.

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