Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Highly stereocontrolled synthesis of trans-enediynes via carbocupration of fluoroalkylated diynes.

ABSTRACT: Treatment of readily prepared (Z)-6-benzyloxy-1,1,1,2-tetrafluoro-6-methyl-2-hepten-4-yne with 1.5 equiv of LHMDS in -78 °C for 1 h gave the corresponding trifluoromethylated diyne in an excellent yield. This diyne was found to be a good substrate for the carbocupration with various higher-ordered cyanocuprates to give the corresponding vinylcuprates in a highly regio- and stereoselective manner. The in situ generated vinylcuprates could react very smoothly with an excess amount of iodine, the vinyl iodides being obtained in high yields. Thus-obtained iodides underwent a very smooth Sonogashira cross-coupling reaction to afford various trans-enediynes in high yields.

SUBMITTER: Konno T

PROVIDER: S-EPMC3558832 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Highly stereocontrolled synthesis of trans-enediynes via carbocupration of fluoroalkylated diynes.

Konno Tsutomu T Kishi Misato M Ishihara Takashi T

Beilstein journal of organic chemistry 20121219

Treatment of readily prepared (Z)-6-benzyloxy-1,1,1,2-tetrafluoro-6-methyl-2-hepten-4-yne with 1.5 equiv of LHMDS in -78 °C for 1 h gave the corresponding trifluoromethylated diyne in an excellent yield. This diyne was found to be a good substrate for the carbocupration with various higher-ordered cyanocuprates to give the corresponding vinylcuprates in a highly regio- and stereoselective manner. The in situ generated vinylcuprates could react very smoothly with an excess amount of iodine, the v ...[more]

PMID: 23365631

Similar Datasets

Synthesis of 5-fluoroalkylated pyrimidine nucleosides via Negishi cross-coupling.

Project description:5-Fluoroalkylated pyrimidine nucleosides (1) have potential as therapeutic agents and molecular imaging agents targeting HSV1-tk suicide gene therapy. Thus, straightforward preparation of 5-fluoroalkylated nucleoside derivatives has been developed. Reported herein are the first examples of Pd-catalyzed Negishi cross-coupling of 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxyuridine (2a) and 3-N-benzoyl-3',5'-di-O-benzoyl-5-iodo-2'-deoxy-2'-fluoroarabinouridine (2b) with unactivated Csp(3) fluoroalkylzinc bromides. This paper demonstrates the first synthesis of six 5-fluoroalkyl-2'-deoxypyrimidine nucleoside derivatives with three to five methylene chain lengths (5). Furthermore, this methodology has been extended to create a series of 13 5-alkyl-substituted nucleosides, including the target nucleosides 5 and 5-silyloxypropyl and 5-cyanobutyl derivatives.

| S-EPMC4122541 | biostudies-literature

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation.

Project description:A new highly diastereoselective synthesis of the polyhydroxylated pyrrolidine alkaloid (±)-codonopsinol B and its N-nor-methyl analogue, starting from achiral materials, is presented. The strategy relies on the trans-stereoselective epoxidation of 2,3-dihydroisoxazole with in situ-generated DMDO, the syn-selective α-chelation-controlled addition of vinyl-MgBr/CeCl3 to the isoxazolidine-4,5-diol intermediate, and the substrate-directed epoxidation of the terminal double bond of the corresponding γ-amino-α,β-diol with aqueous hydrogen peroxide catalyzed by phosphotungstic heteropoly acid. Each of the key reactions proceeded with an excellent diastereoselectivity (dr > 95:5). (±)-Codonopsinol B was prepared in 10 steps with overall 8.4% yield. The antiproliferative effect of (±)-codonopsinol B and its N-nor-methyl analogue was evaluated using several cell line models.

| S-EPMC8630432 | biostudies-literature

Stereocontrolled Synthesis of Fluorinated Isochromans via Iodine(I)/Iodine(III) Catalysis.

Project description:The success of saturated, fluorinated heterocycles in contemporary drug discovery provides a stimulus for creative endeavor in main group catalysis. Motivated by the ubiquity of isochromans across the bioactive small molecule spectrum, the prominence of the anomeric effect in regulating conformation, and the metabolic lability of the benzylic position, iodine(I)/iodine(III) catalysis has been leveraged for the stereocontrolled generation of selectively fluorinated analogs. To augment the current arsenal of fluorocyclization reactions involving carboxylic acid derivatives, the reaction of readily accessible 2-vinyl benzaldehydes is disclosed (up to >95 : 05 d.r. and 97 : 03 e.r.). Key stereoelectronic interactions manifest themselves in the X-ray crystal structures of the products, thereby validating the [CH2 -CHF] fragment as a stereoelectronic mimic of the [O-CH(OR)] acetal motif.

| S-EPMC9401867 | biostudies-literature

Synthesis of 1,3-Diynes via Cadiot-Chodkiewicz Coupling of Volatile, in Situ Generated Bromoalkynes.

Project description:A convenient Cadiot-Chodkiewicz protocol that facilitates the use of low molecular weight alkyne coupling partners is described. The method entails an in situ elimination from a dibromoolefin precursor and immediate subjection to copper-catalyzed conditions, circumventing the hazards of volatile brominated alkynes. The scope of this method is described, and the internal 1,3-diyne products are preliminarily evaluated in ruthenium-catalyzed azide-alkyne cycloadditions.

| S-EPMC6217962 | biostudies-literature

Stereocontrolled Synthesis of (±)-Melokhanine E via an Intramolecular Formal [3 + 2] Cycloaddition.

Project description:A convergent sequence to access the indole alkaloid (±)-melokhanine E in 12-steps (8-step longest linear sequence) and an 11% overall yield is reported. The approach utilizes two cyclopropane moieties as reactive precursors to a 1,3-dipole and imine species to enable stereoselective construction of the core scaffold through a formal [3 + 2] cycloaddition. The natural product was evaluated for its antimicrobial activity based on isolation reports; however, no activity was observed. The reported efforts serve as a synthetic platform to prepare an array of alkaloids bearing this core structural motif.

| S-EPMC7662073 | biostudies-literature

Studies of intramolecular Diels-Alder reactions of nitroalkenes for the stereocontrolled synthesis of trans-decalin ring systems.

Project description:Studies of thermal IMDA cyclizations of (1E,7E)-1-nitro-deca-1,7,9-trienes and (1E,3Z,7E)-1-nitro-deca-1,3,7,9-tetraenes have been examined. Reactions of these nitroalkenes proceed via transition states featuring characteristics of asymmetric stretch asynchronicity and result in stereoselective formation of trans-fused decalin products. A substantial rate acceleration is observed for IMDA cyclizations exemplified by triene 14 due to steric repulsions of substituents in the tethering chain which promote facile stereocontrolled formation of trans-fused 26.

| S-EPMC3081583 | biostudies-literature

Stereocontrolled Synthesis of Kalihinol C.

Project description:We report a concise chemical synthesis of kalihinol C via a possible biosynthetic intermediate, "protokalihinol", which was targeted as a scaffold en route to antiplasmodial analogs. High stereocontrol of the kalihinol framework relies on a heterodendralene cascade to establish the target stereotetrad. Common problems of regio- and chemoselectivity encountered in the kalihinol class are explained and solved.

| S-EPMC5854479 | biostudies-literature

Stereocontrolled Total Synthesis of (-)-Stemaphylline.

Project description:Homologation of readily available ?-boryl pyrrolidines with metal carbenoids is especially challenging even when good leaving groups (Cl- ) are employed. By performing a solvent switch from Et2 O to CHCl3 , efficient 1,2-metalate rearrangement of the intermediate boronate occurs with both halide and ester leaving groups. The methodology was used in the total synthesis of the Stemona alkaloid (-)-stemaphylline in just 11 steps (longest linear sequence), with high stereocontrol (>20:1 d.r.) and 11?% overall yield. The synthesis also features a late-stage lithiation-borylation reaction with a tertiary amine containing carbenoid.

| S-EPMC5484348 | biostudies-literature

Stereocontrolled Synthesis of (+)-Plagiogyrin A.

Project description:Plagiogyrin A (1) was first isolated from the fronds of Plagiogyria matsumureana. Structurally, it features an α-ketoaldehyde functional group in its hemiacetal form, fused in a cis-substituted lactone ring. We have successfully synthesized the skeleton of this natural product by employing a stereocontrolled aldol reaction followed by the installation of the α-ketoaldehyde moiety derived from the mild oxidation of an α-diazoketone. Finally, anhydrous acidic conditions released the protected diol and provided the required cyclized hemiacetal.

| S-EPMC5378675 | biostudies-literature

A stereocontrolled synthesis of (+)-saxitoxin.

Project description:A concise stereoselective total synthesis of (+)-saxitoxin is described. A silver(I)-initiated hydroamination cascade constructs the bicyclic guanidinium ion core from a alkynyl bisguanidine. This sequence creates two C-N bonds, one C-O bond, and three rings and forms a single stereoisomer in a single synthetic transformation. This process enabled us to complete the synthesis of (+)-saxitoxin in 14 steps from N-Boc-l-serine methyl ester.

| S-EPMC3320040 | 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