Ruthenium‐Catalyzed Enantioselective Propargylic Phosphinylation of Propargylic Alcohols with Phosphine Oxides

Abstract

The development of transition metal-catalyzed enantioselective propargylic substitution reactions has gained much progress in recent years, however, no successful example with phosphorus-centered nucleophiles has yet been reported until now. Herein, we report the first successful example of ruthenium-catalyzed enantioselective propargylic substitution reactions of propargylic alcohols with diarylphosphine oxides as phosphorus-centered nucleophiles. This synthetic approach provides a new method to prepare chiral phosphorus-containing organic compounds.

Enantioconvergent Reductive C(sp)−C(sp3) Cross‐Coupling to Access Chiral α‐Alkynyl Phosphonates Under Dual Nickel/Photoredox Catalysis

“…To gain this type of framework, traditional methods usually relied on multistep transformations or nucleophilic additions [8] . Leveraging with an optically active thiolate‐bridged diruthenium complex, Nishibaysashi and Sakata published an intelligent enantioselective propargylic phosphinylation of propargylic alcohols with phosphine oxides to yield the difficult‐to‐obtained chiral α tetrasubstituted phosphorus compounds bearing an alkynyl group (Scheme 1c) [9] . However, the necessity of the formation of ruthenium‐allenylidene intermediate rendered it only suitable for the terminal alkynes.…”

“…[8] Leveraging with an optically active thiolatebridged diruthenium complex, Nishibaysashi and Sakata published an intelligent enantioselective propargylic phosphinylation of propargylic alcohols with phosphine oxides to yield the difficult-to-obtained chiral α tetrasubstituted phosphorus compounds bearing an alkynyl group (Scheme 1c). [9] However, the necessity of the formation of ruthenium-allenylidene intermediate rendered it only suitable for the terminal alkynes. In addition, the essential aryl and trifluoromethyl groups further limited the substrate range.…”

“…[14] First, a diverse array of phosphonates, including dimethyl (4), diethyl (5), and diisobutyl (6) phosphonates can be employed to give a similarly high level of yields and enantioselectivities under these conditions, although processing the dramatically different amounts of steric hindrance. Meanwhile, various silyl substituents, such as trimethyl (7), triethyl (8), tripropyl (9), triphenyl (10), tertbutyldimethyl (11), and tert-butyldiphenyl (12) had no obvious effect on the transformation. In addition, arylated alkynyl bromides (13-20), with either electron-withdrawing or donating substituents on different positions of the aryl group, were also suitable candidates for this C(sp)À (sp 3 ) cross-coupling to give the corresponding products with excellent enantioselectivities, albeit with a bit of erosion of the yields.…”