A Visible‐Light‐Mediated Radical Smiles Rearrangement and its Application to the Synthesis of a Difluoro‐Substituted Spirocyclic ORL‐1 Antagonist
作者:James J. Douglas、Haley Albright、Martin J. Sevrin、Kevin P. Cole、Corey R. J. Stephenson
DOI:10.1002/anie.201507369
日期:2015.12
systems, representing a new disconnection for the synthesis of this versatile moiety. When applied to the target compound, the photochemical step could be conducted on 15 g scale using industrially relevant [Ru(bpy)3Cl2] catalyst loadings of 0.01 mol %. This transformation is part of an overall five‐step route to the antagonist that compares favorably to the current synthetic sequence and demonstrates
Preparative Scale Demonstration and Mechanistic Investigation of a Visible Light-Mediated Radical Smiles Rearrangement
作者:James J. Douglas、Martin J. Sevrin、Kevin P. Cole、Corey R. J. Stephenson
DOI:10.1021/acs.oprd.6b00126
日期:2016.7.15
A visible light-mediated Smiles rearrangement providing the difluoroethanol motif has been shown to reliably operate on preparative scale up to 100 g of starting material. Mechanistic investigation has revealed the reaction proceeds predominantly via a radical chain process that in some instances can be initiated via visible light or thermal activation in the absence of a photocatalyst. The reaction was demonstrated in continuous flow, with visible light and thermal initiation using a thiophene substrate relevant to pharmaceutical development.