Stereoelectronic Effect on Stereoselective Olefination of Ketones Providing Tetrasubstituted Olefins via Ynolates

Stereoelectronic Effect on Stereoselective Olefination of Ketones Providing Tetrasubstituted Olefins via Ynolate

Diastereoselective Construction of 7-Methylenebicyclo[3.2.1]oct-3-en-2-one Derivatives by Palladium-Catalyzed Cyclization of Propargylic Acetates with 2-Oxocyclohex-3-enecarboxylates

The reaction of propargylic acetates with 2-oxocyclohex-3-enecarboxylates in the presence of a palladium catalyst is described. Substituted 7-methylenebicyclo[3.2.1]oct-3-en-2-ones were synthesized in a highly diastereoselective manner

Stereoselective Construction of Substituted Chromans by Palladium-Catalyzed Cyclization of Propargylic Carbonates with 2-(2-Hydroxyphenyl)acetates

Highly substituted chromans have been constructed in a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity

Stereoselective Construction of Substituted Chromans by Palladium-Catalyzed Cyclization of Propargylic Carbonates with 2-(2-Hydroxyphenyl)acetates

Highly substituted chromans have been constructed in a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity

A Novel Tandem [2 + 2] Cycloaddition−Dieckmann Condensation with Ynolate Anions. Efficient Synthesis of Substituted Cycloalkenones and Naphthalenes via Formal [<i>n</i> + 1] Cycloaddition

A novel tandem [2 + 2] cycloaddition−Dieckmann condensation via ynolate anions is described. Ynolate anions are useful for the formation of reactive β-lactone enolates via a pathway not involving the enolization of the corresponding β-lactones. The [2 + 2] cycloaddition of ynolate anions with δ- or γ-keto esters, followed by Dieckmann condensation, gives bicyclic β-lactones, which are easily decarboxylated to produce synthetically useful 2,3-disubstituted cyclopentenones and cyclohexenones in one pot. This tandem reaction was applied to a novel, one-pot synthesis of highly substituted naphthalenes

Diastereoselective Construction of 7-Methylenebicyclo[3.2.1]oct-3-en-2-one Derivatives by Palladium-Catalyzed Cyclization of Propargylic Acetates with 2-Oxocyclohex-3-enecarboxylates

The reaction of propargylic acetates with 2-oxocyclohex-3-enecarboxylates in the presence of a palladium catalyst is described. Substituted 7-methylenebicyclo[3.2.1]oct-3-en-2-ones were synthesized in a highly diastereoselective manner

A Novel Tandem [2 + 2] Cycloaddition−Dieckmann Condensation: Facile One-Pot Process To Obtain 2,3-Disubstituted-2-cycloalkenones from Ynolates

A Novel Tandem [2 + 2] Cycloaddition−Dieckmann Condensation:  Facile One-Pot Process To Obtain 2,3-Disubstituted-2-cycloalkenones from Ynolate

Palladium-Catalyzed Diastereoselective Coupling of Propargylic Oxiranes with Terminal Alkynes

A diastereoselective coupling of propargylic oxiranes with terminal alkynes has been developed with use of a palladium catalyst. The stereochemistries of the resulting 4-alkynyl-substituted 2,3-allenols have been altered depending on the palladium catalyst. An optically active anti-substituted allene was synthesized from the reaction of an enantiomerically enriched propargylic oxirane without loss of chirality

Total Syntheses of Enokipodins A and B Utilizing Palladium-Catalyzed Addition of An Arylboronic Acid to An Allene

The enantioselective total syntheses of enokipodins A and B, α-cuparenone-type sesquiterpenoids with antimicrobial activity, have been achieved. The key step is the enantiospecific construction of the quaternary carbon center using a palladium-catalyzed addition of an arylboronic acid to an allene followed by an Eschenmoser−Claisen rearrangement

Total Synthesis of (−)-Aspidospermine via Diastereoselective Ring-Closing Olefin Metathesis

An enantiocontrolled total synthesis of (−)-aspidospermine has been achieved. The key element of the strategy is the diastereoselective construction of the quaternary stereogenic center employing 1,4-asymmetric induction during the ring-closing olefin metathesis