A palladium-catalyzed cascade approach for the synthesis of 3,3a,4,6,7,8,9,9a-octahydro-1H-benzo[f]isoindole-1,5(2H)-diones

A synthetic method for the preparation of 3,3a,4,6,7,8,9,9a-octahydro-1 H-benzo[ f]isoindole-1,5(2 H)-diones from 1,6-dienes and vinyl iodides is developed using PdCl2(PPh3)2 as the catalyst. The presented approach exhibits a good functional group tolerance and affords moderate yields of the products. A mechanism is also proposed.

Ligand-Free Palladium-Catalyzed Carbonylative Suzuki Couplings of Vinyl Iodides with Arylboronic Acids under Substoichiometric Base Conditions

A ligand-free palladium-catalyzed carbonylation of vinyl iodides with arylboronic acids allowing for the synthesis of chalcones and α-branched enones has been established. This reaction proceeds smoothly under ambient pressure and temperature and even use of substoichiometric base renders the transformation to work well. Importantly, this mild, efficient, operationally simple protocol is suitable for the late-stage functionalization of an epiandrosterone-derived complex molecule.

Oxidative additions of alkynyl/vinyl iodides to gold and gold-catalyzed vinylation reactions triggered by the MeDalphos Ligand

The hemilabile Ad2P(o-C6H4)NMe2 ligand promotes fast, quantitative and irreversible oxidative addition of alkynyl and vinyl iodides to gold. The reaction is general. It works with a broad range of substrates...

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Iron-Catalyzed Carboiodination of Alkynes

An iron-catalyzed carboiodination of alkynes with alkyl iodides­ at room temperature was developed. This method could provide synthetically useful vinyl iodides with general alkyl chains, fluoroalkyl group, ester, and cyano group. Conjugated alkynes or unconjugated alkynes were both suitable for this transformation. A radical pathway was proposed for the mechanism and acetyl tert-butyl peroxide was selected as the radical initiator. Alkenes could also be applied to this chemistry and produce more complex alkyl iodides.