Search

A highly chemo-, regio- and stereoselective reaction for assembling an alkene and alkyne via a cobalt-catalyzed reductive-coupling mode is presented. The methodology could also be used to synthesize six- and seven-membered cyclic lactones and lactams.

An efficient method for the cocyclotrimerization of bicyclic alkenes and benzynes catalyzed by palladium phosphine complexes is described to give the corresponding norbornane anellated 9,10-dihydro-phenanthrene derivatives. For the synthesis of polyaromatics, substituted benzo[b]triphenylenes (8a-f), the [2+2+2] cocyclotrimerization products from oxa- and azabicyclic alkenes can be applied via a simple Lewis acid mediated deoxyaromatization in good yields.

A mild and highly diastereo-selective catalytic intermolecular reductive [3+2] cycloaddition of allenes and enones are demonstrated which is the first report of cobalt-catalyzed cycloaddition of this type. This new reductive cycloaddition reaction underlines the potential of using cobalt as a very user-friendly, inexpensive and efficient catalyst for the formation of carbon-carbon bond and synthesis of carbocycles.

A study is conducted to demonstrate that there are three basic reactions for the alkynes with arynes, namely dehydro Diels-Alder reaction (DDAR), ene, and acetylenic C-H addition reactions. These provide simple and efficient routes for the synthesis of various phenanthrene, phenylallene, and phenylalkyne derivatives.

The article provides information related to cobalt-catalyzed diastereoselective reductive cycloaddition of allenes and enones. The cycloaddition reaction is one of the primary methods to construct five-membered carbocycles, which are common structural cores of a large number of biologically important natural products and target molecules for numerous synthetic studies.

A new cobalt-catalyzed coupling of aryl halides with thiophenols and alkanethiols is reported. A variety of aryl sulfides can be prepared in excellent yields under mild reaction conditions using 1-2 mol % of CoI2(dppe) and Zn. This new cobalt-catalyzed coupling represents an interesting addition to previously known methods to synthesize thioethers. [reaction: see text].

[reaction: see text] o-Allylbiaryl derivatives have been prepared in good to excellent yields by the palladium-catalyzed three-component reaction of allyl halides, benzynes, and aryl organometallic reagents.