Refining Gasoline with Solid Phosphoric Acid Catalyst

1938 ◽  
Vol 30 (11) ◽  
pp. 1316-1317 ◽  
Author(s):  
V. N. Ipatieft ◽  
B. B. Corson
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalyst

The Highly Enantioselective Addition of Indoles toN-Acyl Imines with Use of a Chiral Phosphoric Acid Catalyst

2007 ◽  
Vol 9 (14) ◽  
pp. 2609-2611 ◽  
Author(s):  
Gerald B. Rowland ◽  
Emily B. Rowland ◽  
Yuxue Liang ◽  
Jason A. Perman ◽  
Jon C. Antilla
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalyst ◽  
Chiral Phosphoric Acid ◽  
Enantioselective Addition

scholarly journals QM/MM study on the enantioselectivity of spiroacetalization catalysed by an imidodiphosphoric acid catalyst: how confinement works

2016 ◽  
Vol 14 (11) ◽  
pp. 3031-3039 ◽  
Author(s):  
Luis Simón ◽  
Robert S. Paton
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalyst ◽  
Acid Catalysts ◽  
Chiral Phosphoric Acid

An explanation of why confined imidodiphosphoric acid catalyst succeeds where other chiral phosphoric acid catalysts fail.

Asymmetric N-aminoalkylation of 3-substituted indoles by N-protected N,O-acetals: an access to chiral propargyl aminals

2020 ◽  
Vol 18 (22) ◽  
pp. 4169-4173
Author(s):  
Junxian Yang ◽  
Zeyuan He ◽  
Liang Hong ◽  
Wangsheng Sun ◽  
Rui Wang
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalyst ◽  
Mild Conditions

A direct enantioselective N1 aminoalkylation of 3-substituted indoles is efficiently catalyzed by a phosphoric acid catalyst under mild conditions, which could be applied to the modification of tryptophan containing oligopeptides.

Enantioselective Approaches to 3,4-Annulated Indoles Using Organocatalytic Domino Reactions

Synlett ◽  
2017 ◽  
Vol 28 (13) ◽  
pp. 1530-1543 ◽  
Author(s):  
Mariafrancesca Fochi ◽  
Luca Bernardi ◽  
Lorenzo Caruana
Keyword(s):  
Phosphoric Acid ◽  
Reaction Pathway ◽  
Ergot Alkaloids ◽  
Acid Catalyst ◽  
Secondary Amines ◽  
Domino Reactions ◽  
Structural Framework ◽  
Unique Reaction ◽  
Iminium Ions ◽  
Nitronic Acid

Organocatalytic domino reactions of 4-substituted indoles are summarized in this account. Two reactions have been developed, one with enals, activated by secondary amine catalysts via iminium ions, and one with nitroethene, using a phosphoric acid catalyst. Both reactions required solving the challenge posed by the very low nucleo­philicity of the indole substrates, which bear an electron-withdrawing Michael acceptor at C4. DFT calculations were used to shed light on the unique reaction pathway followed by the phosphoric acid catalyzed transformation, wherein a bicoordinated nitronic acid intermediate was found to evolve preferentially through an intramolecular nitro-Michael reaction, instead of the common tautomerization pathway. These reactions provide new and efficient entries to 3,4-ring-fused indoles in dia­stereo- and enantioenriched form. In more detail, the structures obtained feature a 1,3,4,5-tetrahydrobenzo[cd]indole core, which is present in the structural framework of ergot alkaloids. Indeed, the preparation of an intermediate previously used in ergot alkaloid (6,7-secoagroclavine) synthesis was possible from one of the catalytic adducts.1 Introduction2 Reactions of 4-Substituted Indoles with α,β-Unsaturated Aldehydes Catalyzed by Secondary Amines3 Reactions of 4-Substituted Indoles with Nitroethene Catalyzed by Brønsted Acids4 Conclusion

scholarly journals A chiral phosphoric acid catalyst for asymmetric construction of 1,3-dioxanes

2015 ◽  
Vol 51 (58) ◽  
pp. 11693-11696 ◽  
Author(s):  
Akira Matsumoto ◽  
Keisuke Asano ◽  
Seijiro Matsubara
Keyword(s):  
Phosphoric Acid ◽  
Michael Addition ◽  
Acid Catalyst ◽  
Chiral Phosphoric Acid

A chiral phosphoric acid catalyst enabled enantioselective 1,3-dioxane construction, useful for polyketide motif synthesis, via a hemiacetalization/intramolecular oxy-Michael addition cascade.

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