Category Archives: J Am Chem Soc

Palladium-Catalyzed Anti-Markovnikov Oxidation of Allylic Amides to Protected β-Amino Aldehydes.

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Palladium-Catalyzed Anti-Markovnikov Oxidation of Allylic Amides to Protected β-Amino Aldehydes.

J Am Chem Soc. 2014 Dec 10;136(49):17302-7

Authors: Dong JJ, Harvey EC, Fañanás-Mastral M, Browne WR, Feringa BL

Abstract
A general method for the preparation of N-protected β-amino aldehydes from allylic amines or linear allylic alcohols is described. Here the Pd(II)-catalyzed oxidation of N-protected allylic amines with benzoquinone is achieved in tBuOH under ambient conditions with excellent selectivity toward the anti-Markovnikov aldehyde products and full retention of configuration at the allylic carbon. The method shows a wide substrate scope and is tolerant of a range of protecting groups. Furthermore, β-amino aldehydes can be obtained directly from protected allylic alcohols via palladium-catalyzed autotandem reactions, and the application of this method to the synthesis of β-peptide aldehydes is described. From a mechanistic perspective, we demonstrate that tBuOH acts as a nucleophile in the reaction and that the initially formed tert-butyl ether undergoes spontaneous loss of isobutene to yield the aldehyde product. Furthermore, tBuOH can be used stoichiometrically, thereby broadening the solvent scope of the reaction. Primary and secondary alcohols do not undergo elimination, allowing the isolation of acetals, which subsequently can be hydrolyzed to their corresponding aldehyde products.

PMID: 25384246 [PubMed – indexed for MEDLINE]

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Finding the switch: turning a baeyer-villiger monooxygenase into a NADPH oxidase.

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Finding the switch: turning a baeyer-villiger monooxygenase into a NADPH oxidase.
J Am Chem Soc. 2014 Dec 10;136(49):16966-9
Authors: Brondani PB, Dudek HM, Martinoli C, Mattevi A, Fraaije MW
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Multi-state regulation of the dihydrogen phosphate binding affinity to a light- and heat-responsive bis-urea receptor.

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Multi-state regulation of the dihydrogen phosphate binding affinity to a light- and heat-responsive bis-urea receptor.

J Am Chem Soc. 2014 Dec…

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Disaccharides impact the lateral organization of lipid membranes.

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Disaccharides impact the lateral organization of lipid membranes.

J Am Chem Soc. 2014 Nov 19;136(46):16167-75

Authors: Moiset G, López CA, Bartelds R, Syga L, Rijpkema E, Cukkemane A, Baldus M, Poolman B, Marrink SJ

Abstract
Disaccharides are well-known for their membrane protective ability. Interaction between sugars and multicomponent membranes, however, remains largely unexplored. Here, we combine molecular dynamics simulations and fluorescence microscopy to study the effect of mono- and disaccharides on membranes that phase separate into Lo and Ld domains. We find that nonreducing disaccharides, sucrose and trehalose, strongly destabilize the phase separation leading to uniformly mixed membranes as opposed to monosaccharides and reducing disaccharides. To unveil the driving force for this process, simulations were performed in which the sugar linkage was artificially modified. The availability of accessible interfacial binding sites that can accommodate the nonreducing disaccharides is key for their strong impact on lateral membrane organization. These exclusive interactions between the nonreducing sugars and the membranes may rationalize why organisms such as yeasts, tardigrades, nematodes, bacteria, and plants accumulate sucrose and trehalose, offering cell protection under anhydrobiotic conditions. The proposed mechanism might prove to be a more generic way by which surface bound agents could affect membranes.

PMID: 25316578 [PubMed – indexed for MEDLINE]

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Lipid organization of the plasma membrane.

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Lipid organization of the plasma membrane.

J Am Chem Soc. 2014 Oct 15;136(41):14554-9

Authors: Ingólfsson HI, Melo MN, van Eerden FJ, Arnarez C, Lopez CA, Wassenaar TA, Periole X, de Vries AH, Tieleman DP, Marrink SJ

Abstract
The detailed organization of cellular membranes remains rather elusive. Based on large-scale molecular dynamics simulations, we provide a high-resolution view of the lipid organization of a plasma membrane at an unprecedented level of complexity. Our plasma membrane model consists of 63 different lipid species, combining 14 types of headgroups and 11 types of tails asymmetrically distributed across the two leaflets, closely mimicking an idealized mammalian plasma membrane. We observe an enrichment of cholesterol in the outer leaflet and a general non-ideal lateral mixing of the different lipid species. Transient domains with liquid-ordered character form and disappear on the microsecond time scale. These domains are coupled across the two membrane leaflets. In the outer leaflet, distinct nanodomains consisting of gangliosides are observed. Phosphoinositides show preferential clustering in the inner leaflet. Our data provide a key view on the lateral organization of lipids in one of life’s fundamental structures, the cell membrane.

PMID: 25229711 [PubMed – indexed for MEDLINE]

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Photopharmacology: beyond proof of principle.

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Photopharmacology: beyond proof of principle.
J Am Chem Soc. 2014 Feb 12;136(6):2178-91
Authors: Velema WA, Szymanski W, Feringa BL
Abstract
Pharmacotherapy is often severely hindered… Continue reading

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Nucleic Acid Chemistry in the Organic Phase: From Functionalized Oligonucleotides to DNA Side Chain Polymers.

Nucleic Acid Chemistry in the Organic Phase: From Functionalized Oligonucleotides to DNA Side Chain Polymers.
J Am Chem Soc. 2014 Sep 29;
Authors: Liu K, Zheng L, Liu Q, de Vries JW, Gerasimov JY, Herrmann A
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Reversible photochemical control of singlet oxygen generation using diarylethene photochromic switches.

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Reversible photochemical control of singlet oxygen generation using diarylethene photochromic switches.
J Am Chem Soc. 2014 Jan 22;136(3):910-3
Authors: Hou L, Zhang X, Pijper TC, Browne WR, Feringa … Continue reading

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Uncovering the selection criteria for the emergence of multi-building-block replicators from dynamic combinatorial libraries.

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Uncovering the selection criteria for the emergence of multi-building-block replicators from dynamic combinatorial libraries.

J Am Chem Soc. 2013 Dec…

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Dynamic combinatorial libraries: from exploring molecular recognition to systems chemistry.

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Dynamic combinatorial libraries: from exploring molecular recognition to systems chemistry.

J Am Chem Soc. 2013 Jun 26;135(25):9222-39

Authors: Li J,…

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Evidence for cardiolipin binding sites on the membrane-exposed surface of the cytochrome bc1.

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Evidence for cardiolipin binding sites on the membrane-exposed surface of the cytochrome bc1.

J Am Chem Soc. 2013 Feb 27;135(8):3112-20

Authors: Arnarez…

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Copper-catalyzed enantioselective allyl-allyl cross-coupling.

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Copper-catalyzed enantioselective allyl-allyl cross-coupling.

J Am Chem Soc. 2013 Feb 13;135(6):2140-3

Authors: Hornillos V, Pérez M, Fañanás-Mastral M,…

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Driving unidirectional molecular rotary motors with visible light by intra- and intermolecular energy transfer from palladium porphyrin.

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Driving unidirectional molecular rotary motors with visible light by intra- and intermolecular energy transfer from palladium porphyrin.
J Am Chem Soc. 2012 Oct 24;134(42):17613-9
Authors: Cnossen A, Hou L, Po… Continue reading

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Structural determinants of the supramolecular organization of G protein-coupled receptors in bilayers.

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Structural determinants of the supramolecular organization of G protein-coupled receptors in bilayers.

J Am Chem Soc. 2012 Jul 4;134(26):10959-65

Authors: …

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Z-Selective copper-catalyzed asymmetric allylic alkylation with Grignard reagents.

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Z-Selective copper-catalyzed asymmetric allylic alkylation with Grignard reagents.
J Am Chem Soc. 2012 Mar 7;134(9):4108-11
Authors: Giannerini M, Fañanás-Mastral M, Feringa BL
Abstract
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Molecular view of the role of fusion peptides in promoting positive membrane curvature.

Molecular view of the role of fusion peptides in promoting positive membrane curvature.

J Am Chem Soc. 2012 Jan 25;134(3):1543-52

Authors: Fuhrmans M, Marrink SJ

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Annealing-free high-mobility diketopyrrolopyrrole-quaterthiophene copolymer for solution-processed organic thin film transistors.

Annealing-free high-mobility diketopyrrolopyrrole-quaterthiophene copolymer for solution-processed organic thin film transistors.
J Am Chem Soc. 2011 Feb 23;133(7):2198-204
Authors: Li Y, Sonar P, Singh SP, Soh MS, van Meurs M… Continue reading

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