WebMay 13, 2013 · When the Boland protocol was employed for the semi-reduction of 5 a sluggish reaction was observed; after 24 h reaction time at ambient temperature only a 5% isolated yield of alkene 2 was obtained, together with recovered starting material. Changing the amount of zinc, copper, or silver did not result in an improved Z -selectivity. WebThe catalytic system showed several attractive features such as high activity and selectivity, recyclability, scalability and adaptability to continuous operation under mild reaction …
Ligand‐Controlled Regiodivergence for Catalytic Stereoselective ...
WebOct 24, 2024 · Ligand-controlled regiodivergence has been developed for catalytic semireduction of allenamides with excellent chemo- and stereocontrol. This system also provides an example of catalytic regiodivergent semireduction of allenes for the first time. WebFeb 21, 2024 · The mild catalytic partial reduction of amides to imines has proven to be a challenging synthetic transformation, with many transition metals directly reducing these substrates to amines. Herein, we report a mild, catalytic method for the semireduction of both secondary and tertiary amides via zirconocene hydride catalysis. rbcf tdl
Efficient and exceptionally selective semireduction of alkynes …
WebOct 4, 2024 · This semireduction proceeds chemoselectively in the presence of other functional groups, which are typically reduced using conventional hydrogenations. Isotopic labelling studies support a mechanism where the hydride is delivered to the branched position of a Rh-allyl intermediate. Introduction WebSep 27, 2024 · Abstract We report a chemoselective, phosphine-catalyzed semireduction of primary and secondary propiolamides. In the presence of stoichiometric pinacolborane … WebMar 5, 2013 · The semireduction of alkynes to alkenes is an important synthetic transformation. General catalysts, e.g., Lindlar and P2 nickel, are often non-specific, resulting in isomerization or over-reduction to the alkane; and specific catalysts tend to be scope limited. Therefore, a general method for specific semireduction is needed. rbc from blood test