Indium Tribromide‐Catalysed Transfer‐Hydrogenation: Expanding the Scope of the Hydrogenation and of the Regiodivergent DH or HD Addition to Alkenes

Abstract

The transfer-hydrogenation as well as the regioselective and regiodivergent addition of HÀ D from regiospecific deuterated dihydroaromatic compounds to a variety of 1,1-diand trisubstituted alkenes was realised with InBr 3 in dichloro (m)ethane. In comparison with the previously reported BF 3 •Et 2 O-catalysed process, electron-deficient aryl-substituents can be applied reliably and thereby several restrictions could be lifted, and new types of substrates could be transformed successfully in hydrodeuterogenation as well as deuterohydrogenation transfer-hydrogenation reactions.

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

“…Recently, we reported the highest regioselectivities to date for an alkene transfer hydrodeuteration process, where a [Cu−H] species undergoes syn ‐addition across an alkene, followed by deuterodecupration [35] . We believe the observed regioselectivity is attributed to the high degree of catalyst control in the reaction, where the Cu species adds to the alkenyl carbon positioned α‐to the arene, coupled with the H and D transfer reagents operating at distinct points in the reaction mechanism, which is consistent with other selective transfer hydrodeuteration processes [45–49] . With the groundwork laid for controlling regioselectivity in a Cu‐catalyzed alkene transfer hydrodeuteration reaction, we hypothesized that the first metal‐catalyzed enantioselective synthesis of an enantioisotopomer could be achieved if an appropriate chiral ligand was employed in the reaction.…”

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

“…[35] We believe the observed regioselectivity is attributed to the high degree of catalyst control in the reaction, where the Cu species adds to the alkenyl carbon positioned α-to the arene, coupled with the H and D transfer reagents operating at distinct points in the reaction mechanism, which is consistent with other selective transfer hydrodeuteration processes. [45][46][47][48][49] With the groundwork laid for controlling regioselectivity in a Cu-catalyzed alkene transfer hydrodeuteration reaction, we hypothesized that the first metal-catalyzed enantioselective synthesis of an…”

Recent Developments for the Deuterium and Tritium Labeling of Organic Molecules

“…While showing improved results for electron-rich styrenes compared to the iron-catalyzed procedure, this methodology suffers from a somewhat limited scope, performing less well on electron-deficient substrates and failing for unactivated olefins. This reactivity problem was recently successfully tackled by moving to indium­(III) bromide as a Lewis acidic catalyst along with increasing the temperature . While an explanation for the increased reactivity under these conditions was not provided by the authors, electron-deficient as well as trisubstituted olefins are feasible substrates using the improved methodology.…”

“…This reactivity problem was recently successfully tackled by moving to indium(III) bromide as a Lewis acidic catalyst along with increasing the temperature. 291 While an explanation for the increased reactivity under these conditions was not provided by the authors, electron-deficient as well as trisubstituted olefins are feasible substrates using the improved methodology.…”