Ring Opening Of Oxabicyclic Alkenes Research Articles

Cobalt-Catalyzed Asymmetric Alkynylative Ring Opening of Oxabicyclic Alkenes

Cobalt-Catalyzed Asymmetric Alkynylative Ring Opening of Oxabicyclic Alkenes

ChemInform Abstract: Rhodium‐Catalyzed Enantioselective Nucleophilic Fluorination: Ring Opening of Oxabicyclic Alkenes.

AbstractThe ring opening is promoted by NEt3·HF and affords 1,2‐dihydronaphthalene structures in the first step.

Rhodium‐Catalyzed Enantioselective Nucleophilic Fluorination: Ring Opening of Oxabicyclic Alkenes

Enantioselektive Fluorierungen wurden durch die RhI-katalysierte Ringöffnung von oxabicyclischen Alkenen unter der Einwirkung von Et3N⋅3 HF erreicht. Die chiralen fluorierten Grundstrukturen wurden unter milden Reaktionsbedingungen in Standard-Glaskolben erhalten und dienten als Bausteine für verschiedene chirale fluorierte Zielstrukturen. cod=Cyclooctadien, ppf=Phenylphosphanylferrocen, THF=Tetrahydrofuran. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Rhodium‐Catalyzed Enantioselective Nucleophilic Fluorination: Ring Opening of Oxabicyclic Alkenes

Done with 'F'lair: Enantioselective fluorination was achieved by RhI-catalyzed ring opening of oxabicyclic alkenes using Et3N⋅3 HF. The chiral fluorinated scaffolds were obtained under mild reaction conditions in standard glass vessels, and served as useful building blocks for various chiral fluorinated targets. cod=cycloocta-1,5-diene, ppf=phenylphosphinoferrocene, THF=tetrahydrofuran.

ChemInform Abstract: Copper‐Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Organolithium Reagents.

AbstractA highly regio‐, enantio‐, and anti‐selective procedure for the synthesis of the compounds (III) is presented.

Asymmetric Ring Opening of Oxabicyclic Alkenes with Organolithium Reagents

Asymmetric Ring Opening of Oxabicyclic Alkenes with Organolithium Reagents

Copper-catalyzed asymmetric ring opening of oxabicyclic alkenes with organolithium reagents

A highly efficient method is reported for the asymmetric ring opening of oxabicyclic alkenes with organolithium reagents. Using a copper/chiral phosphoramidite complex together with a Lewis acid (BF(3)·OEt(2)), full selectivity for the anti isomer and excellent enantioselectivities were obtained for the ring opened products.

Ring Opening of Oxabicyclic Alkenes Catalyzed by Multinuclear Complexes

This paper describes a new way to accomplish the asymmetric ring opening of oxabicyclic alkene compounds with dialkyl zinc. Multinuclear Pd/Zn complexes using a BINOL derivative as ligands were proposed to be the effective catalyst. This procedure features simple ligand synthesis, high efficiency, and enantioselectivity.

ChemInform Abstract: Highly Enantioselective Copper‐Catalyzed Ring Opening of Oxabicyclic Alkenes with Grignard Reagents.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Highly Enantioselective Copper‐Catalyzed Ring Opening of Oxabicyclic Alkenes with Grignard Reagents

A highly efficient copper-catalyzed enantioselective ring opening of oxabicylic alkenes with Grignard reagents has been developed by using chiral spiro phosphine ligands. Excellent trans selectivities, good yields, and high enantioselectivities are obtained for a broad range of Grignard reagents under mild reaction conditions. The catalyst system shows an extraordinary activity and the TON of the reaction reaches 9000.

Palladacycle as Highly Efficient Catalyst for Ring Opening of Oxabicyclic Alkenes with Organozinc Halides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Palladacycle as highly efficient catalyst for ring opening of oxabicyclic alkenes with organozinc halides

Ring opening reaction of oxabicylic alkenes 4 with in situ prepared organozinc halides 5 was catalyzed by palladacycle 3 with high efficiency. Good yields of the corresponding 1,2-dihydronaphth-1-ols ( 6) were provided when as low as 0.05 mol% of palladacycle 3 was used. 31P NMR study showed that the skeleton of 3 remained intact in the reaction, which implied that palladacycle 3 did not serve as a catalyst precursor but a catalyst in the reaction.

Pd-Catalyzed Ring Opening of Oxa- and Azabicyclic Alkenes with Aryl and Vinyl Halides: Efficient Entry to 2-Substituted 1,2-Dihydro-1-naphthols and 2-Substituted 1-Naphthols

An efficient syntheses of 2-substituted 1,2-dihydro-1-naphthols and 2-substituted 1-naphthols has been developed that involves the sequential palladium-catalyzed ring opening of oxabicyclic alkenes with aryl and vinyl halides followed by oxidation of with IBX. In the first step of the sequence, a combination of Pd(OAc)2, PPh3, Zn, and PMP in dry DMF was employed to catalyze the ring opening of 7-oxabenzonorbornadienes with aryl and vinyl halides to afford the corresponding cis-2-substituted 1,2-dihydronaphthols in good to excellent yields. These reactions occurred under very mild conditions with a variety of aryl halides bearing electron-withdrawing or -donating groups. Similarly, a 7-azabenzonorbornadiene substituted with an electron-withdrawing group on the nitrogen atom underwent facile ring-opening reaction with aryl halides to provide cis-2-substituted (1,2-dihydro-1-naphthyl)carbamates in excellent yields. Oxidation of the intermediate 1,2-dihydro-1-naphthols using IBX yielded the corresponding 2-substituted 1-naphthols in good to excellent yields.

Copper‐Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Grignard Reagents.

Simple Grignard reagents were applied in copper-catalyzed asymmetric ring-opening reactions of oxabenzonorbornadiene derivatives using spiro phosphoramidite ligands. Excellent anti-stereoselectivities and good enantioselectivities were achieved.

Copper-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Grignard Reagents.

Copper-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Grignard Reagents.

Copper-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Grignard Reagents

[reaction: see text] Simple Grignard reagents were applied in copper-catalyzed asymmetric ring-opening reactions of oxabenzonorbornadiene derivatives using spiro phosphoramidite ligands. Excellent anti-stereoselectivities and good enantioselectivities were achieved.

Palladium‐Catalyzed Enantioselective Ring Opening of Oxabicyclic Alkenes with Organozinc Halides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Rhodium‐Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Sulfur Nucleophiles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Palladium-catalyzed enantioselective ring opening of oxabicyclic alkenes with organozinc halides.

Palladium-catalyzed asymmetric ring opening of oxabenzonorbornadienes with readily available organozinc halides under mild conditions in the presence of (S)-Pr(i)-PHOX produces the corresponding 1,2-dihydronaphth-1-ols in good yield and high enantioselectivity. [reaction: see text]

Rhodium-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Sulfur Nucleophiles

The synthesis of 2-sulfanyl-1,2-dihydro-naphthalen-1-ols is described. This methodology is based on rhodium catalysis and enables various thiols to undergo an asymmetric SN2' ring opening of oxabenzonorbornadiene. Under the reaction conditions ([Rh(COD)Cl](2) (2.5 mol %), (S)-(R)-PPF-P(t)Bu(2) (6 mol %), AgOTf (7 mol %), NH(4)I (1.7 equiv), galvinoxyl (5 mol %), THF, 85 degrees C), aryl- and alkyl-sulfide adducts are obtained in good to excellent yield and in high enantiomeric excess (>90% ee).