Simple, Chemoselective Hydrogenation with Thermodynamic Stereocontrol

Abstract

Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.

Syntheses and biological studies of marine terpenoids derived from inorganic cyanide

“…Whereas carbonyls undergo single-electron reduction at cryogenic temperatures in liquid ammonia, alkene 112 requires more activation energy–a balmy 16 °C in ethylamine–to initiate reduction. Although this energy barrier usually limits functional group compatibility, xcii there are no easily reducible groups in 112 and therefore the reaction proceeds cleanly to 111 . It is noteworthy that the stereogenic methyl of 111 possesses the thermodynamically preferred equatorial stereochemistry, even though Piers had observed selectivity for the equatorial-axial dimethyl cyclohexane 120 (see 119 → 120 + 121 ).…”

Proton-Coupled Electron Transfer in Organic Synthesis: Fundamentals, Applications, and Opportunities

“…As such, few if any HAT donors have been shown to be competent to activate ketones, imines, arenes, or certain classes of olefins [23][24][25][26] via HAT. In fact, the weakest, well-characterized metal hydride is Norton's H-V(CO) 4 (dppb), which features a V-H BDFE of 50 kcal mol −1 [27].…”

“…Copyright 2012 American Chemical Society. Phenol model systems capable of intramolecular hydrogen boding synthesized by Matsumura (22)(23)(24)(25) and as model systems for the study of PCET in biological contexts. Variation of the amine donor allows for deep interrogation of hydrogen bonding on PCET processes.…”

Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron‐Catalyzed Reductive anti‐Carbozincation of Terminal Alkynes and Base‐Metal‐Catalyzed Negishi Cross‐Coupling

“…However, the lowering of the loading of bipy or CuI led to the decrease of yields (Table S1, entries 10 and 11). Other Cu catalysts were also screened but they did not catalyze the reactions as efficiently as CuI (Table S1, entries [12][13][14][15][16][17][18]. The use of other Zn activating reagents, bromo-and chlorotrimethylsilane (TMSBr and TMSCl), did not lead to a higher yielder yield compared to TMSI (Table S1, entries 19 and 20).…”