Hydroformylation of alkynes is an underdeveloped atom-economic and redox-neutral method to prepare enals. Applying a new electron poor self-assembling ligand system provides the first general rhodium-catalyst for the chemo- and stereoselective hydroformylation of dialkyl- as well as diaryl-substituted alkynes to furnish enals in excellent chemo- and stereoselectivity.
Syngas‐Free Highly Regioselective Rhodium‐Catalyzed Transfer Hydroformylation of Alkynes to α,β‐Unsaturated Aldehydes
作者:Guangying Tan、Yimin Wu、Yang Shi、Jingsong You
DOI:10.1002/anie.201902553
日期:2019.5.27
fundamental and important reaction in both academic research and industry. Conventional methods focus on the conversion of alkynes, CO, and H2 into α,β‐unsaturated aldehydes, but they often suffer from problems associated with operation, regioselectivity, and chemoselectivity. Herein, we disclose an operationally simple, mild, and syngas‐free rhodium‐catalyzed reaction for the hydroformylation of alkynes
Atom‐efficient: A selective palladium catalyst system is used for the hydroformylation of alkynes (see picture). In this syngas reaction, various alkynes were smoothly transformed to synthetically interesting α,β‐unsaturated aldehydes in good yields with high regio‐ and stereoselectivity.
A new porousorganicpolymer supported rhodium catalyst (Rh/POL-BINAPa&PPh3) has been developed for the hydroformylation of various alkynes to afford the corresponding α,β-unsaturated aldehydes with high chem- and stereoselectivity, excellent catalytic activity and good reusability (10 cycles). The heterogeneouscatalyst exhibited more catalytic activity than the comparable homogeneous Rh/BINAPa/PPh3
(E)‐Trisubstituted allylicalcohols are commonly prepared from the corresponding (E)‐enals, themselves readily accessible by a simple aldol condensation reaction. We demonstrate that these very same (E)‐enals can be converted into (Z)‐trisubstituted allylic acetates (and thus alcohols) by a ruthenium‐catalyzed 1,4‐hydrogenation of the corresponding dienol acetates. This simple solution to a long‐lasting