Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Stereoselective Alkylation of Chiral Titanium(IV) Enolates with tert-Butyl Peresters.

ABSTRACT: Here, we present a new stereoselective alkylation of titanium(IV) enolates of chiral N-acyl oxazolidinones with tert-butyl peresters from Cα-branched aliphatic carboxylic acids, which proceeds through the decarboxylation of the peresters and the subsequent formation of alkyl radicals to produce the alkylated adducts with an excellent diastereoselectivity. Theoretical calculations account for the observed reactivity and the outstanding stereocontrol. Importantly, the resultant compounds can be easily converted into ligands for asymmetric and catalytic transformations.

SUBMITTER: Perez-Palau M

PROVIDER: S-EPMC8609576 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Di-?-methanolato-bis[(2-tert-butyl-6-methylphenolato-?O)methyl-titanium(IV)].

Project description:The molecule of the title compound, [Ti2(CH3)2(CH3O)2(C11H15O)4] or {[Ti(Me)(?-OCH3)(OC6H3CMe3-2-Me-6)]2}, has a centrosymmetric, dimeric structure with a distorted square pyramidal array about each titanium atom. The methoxide ligands form an asymmetric bridge between the two Ti(IV) atoms [Ti-O bond lengths of 1.9794?(12) and 2.0603?(12)?Å] with the two phenolato ligands occupying the remaining basal sites [Ti-O 1.8218?(11) and 1.8135?(11)?Å]. The Ti-O-C phenolato bond angles are similar at 161.24?(10) and 160.66?(11)°. The methyl ligand attached to the metal atom has a Ti-C bond length of 2.0878?(17)?Å.

| S-EPMC3790360 | biostudies-literature

Synthesis of chiral malonates by α-alkylation of 2,2-diphenylethyl tert-butyl malonates via enantioselective phase-transfer catalysis

Project description:An efficient synthetic approach for chiral malonates was established via enantioselective phase transfer catalysis. The α-alkylation of 2,2-diphenylethyl tert-butyl α-methylmalonates with (S,S)-3,4,5-trifluorophenyl-NAS bromide as a phase-transfer catalyst under phase-transfer catalytic conditions successfully produced corresponding α-methyl-α-alkylmalonates; these compounds are versatile chiral building blocks containing a quaternary carbon center in high chemical yields (up to 99%) with excellent enantioselectivities (up to 98% ee). α,α-Dialkylmalonates were selectively hydrolyzed to the corresponding chiral malonic monoacids under basic (KOH/MeOH) and acidic conditions (TFA/CH2Cl2), showing the practicality of the method.

| S-EPMC10285525 | biostudies-literature

Stereoselective RNA Reaction with Chiral 2'-OH Acylating Agents

Project description:The reactivity of RNA 2'-OH groups with acylating agents has recently been investigated for high-yield conjugation of RNA strands. To date, only achiral molecules have been studied for this reaction, despite the complex chiral structure of RNA. Here we prepare a set of chiral acylimidazoles and study their stereoselectivity in RNA reactions. Reactions performed with unfolded and folded RNAs reveal that positional selectivity and reactivity vary widely with local RNA macro-chirality. We further document remarkable effects of chirality on reagent reactivity, identifying an asymmetric reagent with 1000-fold greater reactivity than prior achiral reagents. In addition, we identify a chiral compound with higher RNA structural selectivity than any previously reported RNA-mapping species. Further, azide-containing homologs of a chiral dimethylalanine reagent were synthesized and applied to local RNA labeling, displaying 92% yield and 16:1 diastereoselectivity. The results establish that reagent stereochemistry and chiral RNA structure are critical elements of small molecule-RNA reactions, and demonstrate new chemical strategies for selective RNA modification and probing.

2023-11-14 | GSE247565 | GEO

catena-Poly[[di-tert-butyl-tin(IV)]-μ-oxalato].

Project description:The title compound, [Sn(C4H9)2(C2O4)] n , an unexpected side product in the reaction of di-tert-butyl-tin(IV) oxide with nitric acid, represents the first diorganotin(IV) oxalate to be structurally characterized. The Sn(IV) atom of the one-dimensional coordination polymer is located on a mirror plane and is coordinated by two chelating oxalate ions with two rather different Sn-O bond lengths of 2.150 (1) and 2.425 (1) Å, and two t-butyl groups with Sn-C bond lengths of 2.186 (2) and 2.190 (2) Å. The coordination polyhedron around the Sn(IV) atom is a distorted tetra-gonal disphenoid. The centrosymmetric oxalate ion also has an asymmetric coordination geometry, as reflected by the two slightly different C-O bond lengths of 1.242 (2) and 1.269 (2) Å. The chains of the polymer propagate along the b-axis direction. Only van der Waals inter-actions are observed between the chains.

| S-EPMC3998617 | biostudies-literature

Titanium(IV)-catalyzed stereoselective synthesis of spirooxindole-1-pyrrolines.

Project description:A stereoselective cyclization between alkylidene oxindoles and 5-methoxyoxazoles has been developed using catalytic titanium(IV) chloride (as low as 5 mol %) to afford spiro[3,3'-oxindole-1-pyrrolines] in excellent yield (up to 99%) and diastereoselectivity (up to 99:1). Using a chiral scandium(III)-indapybox/BArF complex affords enantioenriched spirooxindole-1-pyrrolines where a ligand-induced reversal of diastereoselectivity is observed. This methodology is further demonstrated for the synthesis of pyrrolines from malonate alkylidene and coumarin derivatives.

| S-EPMC4275133 | biostudies-other

Dichloridobis(di-tert-butyl-methyl-phosphine oxide-?O)diphenyl-tin(IV).

Project description:The complete mol-ecule of the title compound, [Sn(C(6)H(5))(2)Cl(2)(C(9)H(21)OP)(2)], is generated by crystallographic inversion symmetry, the Sn atom is located on a special position of site symmetry . The Sn atom adopts an all-trans SnC(2)O(2)Cl(2) octa-hedral geometry. As a consequence of the bulky substituents at the O atom, the P-O-Sn bond angle is 163.9?(3)°.

| S-EPMC2961504 | biostudies-literature

(N-Benzyl-N-ethyl-dithio-carbamato)di-tert-butyl-chloridotin(IV).

Project description:The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)Cl(C(10)H(12)NS(2))], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C-H⋯π contacts link centrosymmetrically related mol-ecules into dimeric aggregates.

| S-EPMC3051941 | biostudies-literature

Di-tert-butyl-chlorido(N,N-dibenzyl-dithio-carbamato)tin(IV).

Project description:The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)(C(15)H(14)NS(2))Cl], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl atom and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former.

| S-EPMC3052046 | biostudies-literature

(tert-Butyl-imido)bis-(η-cyclo-penta-dien-yl)pyridine-zirconium(IV).

Project description:The title compound, [Zr(C(5)H(5))(2)(C(4)H(9)N)(C(5)H(5)N)], was obtained from the reaction of (C(5)H(5))(2)Zr(py)(η(2)-Me(3)SiC(2)SiMe(3)) (py is pyridine) and (t)BuN=C=N(t)Bu alongside the formation of (C(5)H(5))(2)Zr(CN(t)Bu)(η(2)-Me(3)SiC(2)SiMe(3)). The zirconium atom is coordinated in a distorted tetra-hedral geometry by two cyclo-penta-dienyl ligands, a pyridine ligand, and a tert-butyl-imido ligand via a Zr=N double bond. The tert-butyl group is disordered over two positions in a 0.634 (5):0.366 (5) ratio.

| S-EPMC3007953 | biostudies-literature

Di-tert-butyl-chlorido(pyrrolidine-1-dithio-carboxyl-ato-κS,S')tin(IV).

Project description:The title compound, [Sn(C(4)H(9))(2)(C(5)H(8)NS(2))Cl], contains two mol-ecules in the asymmetric unit, with similar conformations. In both mol-ecules, the Sn atom adopts a distorted trigonal-bipyramidal geometry arising from two C atoms, one Cl atom and two S atoms from the bidentate dithio-carbamate ligand, with one Sn-S bond much longer than the other. One C atom of the pyrrolidine ring is disordered equally over two sites.

| S-EPMC2914963 | 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