Cyclocarbopalladation of Alkynes: A Stereoselective Method for Preparing Dibenzoxapine Containing Tetrasubstituted Exocyclic Alkenes
摘要:
A palladium-catalyzed cascade carbometalation-cross coupling of alkyne route was developed for the preparation of tetrasubstituted exocyclic alkenes with high stereo- and regiocontrol. The effectiveness of this novel methodology was demonstrated by the synthesis of a number of dibenzoxapines in sufficient quantities to support their further development.
An Iron-Catalyzed Bond-Making/Bond-Breaking Cascade Merges Cycloisomerization and Cross-Coupling Chemistry
作者:Pierre-Georges Echeverria、Alois Fürstner
DOI:10.1002/anie.201604531
日期:2016.9.5
reaction cascade that results in the net formation of two new C−C bonds while a C−Z bond in the substrate backbone is broken. Not only does this new manifold lend itself to the extrusion of heteroelements (Z=O, NR), but it can even be used for the cleavage of activatedC−C bonds. The reaction likely proceeds via metallacyclic intermediates, the iron center of which gains ate character before reductive elimination
An Intra/Intermolecular Suzuki Sequence to Benzopyridyloxepines Containing Geometrically Pure Exocyclic Tetrasubstituted Alkenes
作者:Matthew W. Carson、Matthew W. Giese、Michael J. Coghlan
DOI:10.1021/ol800834q
日期:2008.7.3
A route to enable the preparation of 5-benzylidenyl-benzopyridyloxepine analogues was developed to continue our research in the field of nuclear hormone receptor modulators. The key steps are 1) a syn-stereoselective diboration of a tethered aryl alkyne; 2) an intramolecular Suzuki cross-coupling reaction, which forms in a stereo- and regiocontrolled fashion, the 5-exoalkylidenyl 7-membered ring imbedded
Treatment of 2-alkynylphenol with an alkyl Grignard reagent in the presence of a catalytic amount of manganese(II) chloride provided 2-(2-alkyl-1-alkenyl)phenol in good yield. Alkylmagnesation proceeded with high regio- and stereoselectivities.
Ni-Catalyzed Cycloisomerization between 3-Phenoxy Acrylic Acid Derivatives and Alkynes via Intramolecular Cleavage and Formation of the C–O Bond To Give 2,3-Disubstituted Benzofurans
based on transition-metal-catalyzed C-Obondcleavage have attracted much attention as a new synthetic method. Until now, several intermolecular reactions via C-Obondcleavage of aryl ethers, alkenyl ethers, esters, and others have been reported. Here we report an unprecedented C-Obondcleavage of 3-phenoxy acrylic acid derivatives, followed by intramolecular C-Obond formation with alkynes. This reaction