Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

1,2- or 1,3-Hydride Shifts: What Controls Guaiane Biosynthesis?

ABSTRACT: A systematic computational study addressing the entire chemical space of guaianes in conjunction with an analysis of all known compounds shows that 1,3-hydride shifts are rare events in guaiane biosynthesis. As demonstrated here, 1,3-hydride shifts towards guaianes can only be realized for two stereochemically well defined out of numerous possible stereoisomeric skeletons. One example is given by the mechanism of guaia-4(15)-en-11-ol synthase from California poplar, an enzyme that yields guaianes with unusual stereochemical properties. The general results from DFT calculations were experimentally verified through isotopic-labeling experiments with guaia-4(15)-en-11-ol synthase.

SUBMITTER: Xu H

PROVIDER: S-EPMC8362104 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

1,2- or 1,3-Hydride Shifts: What Controls Guaiane Biosynthesis?

Xu Houchao H Goldfuss Bernd B Dickschat Jeroen S JS

Chemistry (Weinheim an der Bergstrasse, Germany) 20210526 38

A systematic computational study addressing the entire chemical space of guaianes in conjunction with an analysis of all known compounds shows that 1,3-hydride shifts are rare events in guaiane biosynthesis. As demonstrated here, 1,3-hydride shifts towards guaianes can only be realized for two stereochemically well defined out of numerous possible stereoisomeric skeletons. One example is given by the mechanism of guaia-4(15)-en-11-ol synthase from California poplar, an enzyme that yields guaiane ...[more]

PMID: 33929065

Similar Datasets

4,9-Dioxa-1,3(1,2)-dibenzena-2(4,5)-1,3-oxazolidinacyclononaphane.

Project description:The oxazole ring in the title compound, C(20)H(23)NO(3), adopts an envelope conformation while the 12-membered ring is in a chair conformation. The dihedral angle between the benzene rings is 37.8 (1)°. The crystal structure displays inter-molecular C-H⋯O hydrogen bonding.

| S-EPMC3051461 | biostudies-literature

Retracted Article: Synthesis of deuterated isopentyl pyrophosphates for chemo-enzymatic labelling methods: GC-EI-MS based 1,2-hydride shift in epicedrol biosynthesis.

Project description:A sesquiterpene epicedrol cyclase mechanism was elucidated based on the gas chromatography coupled to electron impact mass spectrometry fragmentation data of deuterated (2H) epicedrol analogues. The chemo-enzymatic method was applied for the specific synthesis of 8-position labelled farnesyl pyrophosphate and epicedrol. EI-MS fragmentation ions compared with non-labelled and isotopic mass shift fragments suggest that the 2H of C6 migrates to the C7 position during the cyclization mechanism.

| S-EPMC9071075 | biostudies-literature

1,3-Difunctionalization of [1.1.1]propellane through iron-hydride catalyzed hydropyridylation.

Project description:Current methodologies for the functionalization of [1.1.1]propellane primarily focus on achieving 1, 3-difunctionalized bicyclo[1.1.1]pentane or ring-opened cyclobutane moiety. Herein, we report an innovative approach for the 1, 3-difunctionalization of [1.1.1]propellane, enabling access to a diverse range of highly functionalized cyclobutanes via nucleophilic attack followed by ring opening and iron-hydride hydrogen atom transfer. To enable this method, we developed an efficient iron-catalyzed hydropyridylation of various alkenes for C - H alkylation of pyridines at the C4 position, eliminating the need for stoichiometric quantities of oxidants or reductants. Mechanistic investigations reveal that the resulting N-centered radical serves as an effective oxidizing agent, facilitating single-electron transfer oxidation of the reduced iron catalyst. This process efficiently sustains the catalytic cycle, offering significant advantages for substrates with oxidatively sensitive functionalities that are generally incompatible with alternative approaches. The strategy presented herein is not only mechanistically compelling but also demonstrates broad versatility, highlighting its potential for late-stage functionalization.

| S-EPMC11252317 | biostudies-literature

Copper Hydride Catalyzed Enantioselective Synthesis of Axially Chiral 1,3-Disubstituted Allenes.

Project description:The general enantioselective synthesis of axially chiral disubstituted allenes from prochiral starting materials remains a long-standing challenge in organic synthesis. Here, we report an efficient enantio- and chemoselective copper hydride catalyzed semireduction of conjugated enynes to furnish 1,3-disubstituted allenes using water as the proton source. This protocol is sufficiently mild to accommodate an assortment of functional groups including keto, ester, amino, halo, and hydroxyl groups. Additionally, applications of this method for the selective synthesis of monodeuterated allenes and chiral 2,5-dihydropyrroles are described.

| S-EPMC6748664 | biostudies-literature

8-Bromo-1,3-diphenyl-2,3-dihydro-1H-naphtho-[1,2-e][1,3]oxazine.

Project description:The title compound, C(24)H(18)BrNO, consists of an envelope-configured oxazine ring with a fused 8-bromo-1,3-diphenyl group and two bonded phenyl rings. The dihedral angles between the mean planes of the 8-bromo-1,3-diphenyl and the phenyl rings are 54.5 (6) and 87.4 (8)°, respectively. The oxazine is essentially coplanar with the 8-bromo-1,3-diphenyl [dihedral angle = 9.4 (1)°]. Weak C-H⋯π inter-actions contribute to the crystal packing.

| S-EPMC3007280 | biostudies-literature

1,3-Di-3-pyridyl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazine.

Project description:In the crystal structure of the title compound, C(22)H(17)N(3)O, the oxazine ring has a half-chair conformation. The dihedral angles between the best least-squares plane through the pyridine rings and the planar part (O-C-C-C-N) of the oxazine ring are 72.14 (6) and 35.44 (7)°, the smaller angle involving the pyridine ring adjacent to the oxazine O atom. The mol-ecule has two stereogenic centers at the oxazine carbons, RS and SR. The crystal packing reveals that symmetry-related mol-ecules are linked by inter-molecular N-H⋯N hydrogen bonds to form chains parallel to the b axis.

| S-EPMC2960797 | biostudies-literature

2-Benzyl-1,3-diphenyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazine.

Project description:In the title compound, C(31)H(25)NO, the oxazine ring adopts a half-chair conformation. The dihedral angles between the phenyl rings and the naphthyl ring system are 70.89 (8), 37.34 (10) and 9.42 (10)°. The crystal structure is stabilized by an aromatic π-π stacking inter-action, with a centroid-centroid distance of 3.879 (3) Å.

| S-EPMC2977269 | biostudies-literature

2-Butyl-1,3-diphenyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazine.

Project description:In the title compound, C(28)H(27)NO, the oxazine ring adopts a half-chair conformation. The dihedral angles between the phenyl rings and the naphthyl ring system are 15.34 (1) and 76.51 (1)°.

| S-EPMC2959405 | biostudies-literature

Repercussion of a 1,3-Hydrogen Shift in a Hydride-Osmium-Allenylidene Complex.

Project description:An unusual 1,3-hydrogen shift from the metal center to the Cβ atom of the C3-chain of the allenylidene ligand in a hydride-osmium(II)-allenylidene complex is the beginning of several interesting transformations in the cumulene. The hydride-osmium(II)-allenylidene complex was prepared in two steps, starting from the tetrahydride dimer [(Os(H···H){κ3-P,O,P-[xant(P i Pr2)2]})2(μ-Cl)2][BF4]2 (1). Complex 1 reacts with 1,1-diphenyl-2-propyn-1-ol to give the hydride-osmium(II)-alkenylcarbyne [OsHCl(≡CCH=CPh2){κ3-P,O,P-[xant(P i Pr2)2]}]BF4 (2), which yields OsHCl(=C=C=CPh2){κ3-P,O,P-[xant(P i Pr2)2]} (3) by selective abstraction of the Cβ-H hydrogen atom of the alkenylcarbyne ligand with K t BuO. Complex 3 is metastable. According to results of DFT calculations, the migration of the hydride ligand to the Cβ atom of the cumulene has an activation energy too high to occur in a concerted manner. However, the migration can be catalyzed by water, alcohols, and aldehydes. The resulting alkenylcarbyne-osmium(0) intermediate is unstable and evolves into a 7:3 mixture of the hydride-osmium(II)-indenylidene OsHCl(=CIndPh){κ3-P,O,P-[xant(P i Pr2)2]} (4) and the osmanaphthalene OsCl(C9H6Ph){κ3-P,O,P-[xant(P i Pr2)2]} (5). Protonation of 4 with HBF4 leads to the elongated dihydrogen complex [OsCl(η2-H2)(=CIndPh){κ3-P,O,P-[xant(P i Pr2)2]}]BF4 (6), while the protonation of 5 regenerates 2. In contrast to 4, complex 6 evolves to a half-sandwich indenyl derivative, [Os(η5-IndPh)H{κ3-P,O,P-[xant(P i Pr2)2]}][BF4]Cl (7). Phenylacetylene also provokes the 1,3-hydrogen shift in 3. However, it does not participate in the migration. In contrast to water, alcohols, and aldehydes, it stabilizes the resulting alkenylcarbyne to afford [Os(≡CCH=CPh2)(η2-HC≡CPh){κ3-P,O,P-[xant(P i Pr2)2]}]Cl (8).

| S-EPMC9180373 | biostudies-literature

Copper-catalyzed enantioselective 1,2-borylation of 1,3-dienes.

Project description:A highly enantioselective Cu-catalyzed borylation of 2-substituted 1,3-dienes is reported. The use of a chiral phosphanamine ligand is essential in achieving high chemo-, regio-, diastereo- and enantioselectivity. It provides access to a variety of homoallylic boronates in consistently high yield and enantiomeric excess with 2-aryl and 2-heteroaryl 1,3-dienes as well as sterically demanding 2-alkyl 1,3-dienes. Preliminary investigations based on a non-linear effect study point to a mechanism involving more than one metal center.

| S-EPMC6001400 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data