Rhodium‐Catalyzed Hydroformylation of 1,1‐Disubstituted Allenes Employing the Self‐Assembling 6‐DPPon System

Abstract

A rhodium-catalyzed hydroformylation of 1,1-disubstituted allenes is reported. Using a Rh(I)/6-DPPon catalyst system, one can obtain β,γ-unsaturated aldehydes in high regio- and chemoselectivity. The Z-configured product is formed with up to >95% selectivity when unsymmetrically 1,1-disubstituted allenes are submitted to the reaction conditions. This is the first time that these interesting building blocks are accessible by hydroformylation of allenes. The utility of this methodology is demonstrated by further transformations of one of the obtained products.

Chemo-, Regio-, and Enantioselective Rhodium-Catalyzed Allylation of Pyridazinones with Terminal Allenes

“…Hydrogenation, using 10% wt Pd/C at 0 °C, gave N -alkylpyridazin-one ( 4a ) in 96% yield while hydroxylation via hydroboration/oxidation furnished 78% of the anti-Markovnikov alcohol ( 4b ). N -Allyl pyridazinone was also found to be compatible with our hydroformylation and ozonolysis conditions, giving the corresponding aldehydes ( 4c and 4d ), by using either our self-assembly [Rh­(CO) 2 acac]/6-DPPon catalyst system or O 3 /PPh 3 , in 91% and 82% yields, respectively.…”

Gold(I)‐Catalyzed Cycloisomerization of 3‐Alkoxyl‐1,6‐diynes: A Facile Access to Bicyclo[2.2.1]hept‐5‐en‐2‐ones

“…(2)]. [12] The structural assignment of compound 4 was further confirmed by single-crystal X-ray structure analysis. [13] Preliminary mechanistic studies are shown in Scheme 3.…”

Metal-Catalyzed Intermolecular Hydrofunctionalization of Allenes: Easy Access to Allylic Structures via the Selective Formation of C–N, C–C, and C–O Bonds

“…It was applied to the synthesis of substrates of interest such as (-)-menthone, (+)-camphor and estrone derivatives. 196 The rhodium-catalyzed hydroformylation was also extended to 1,1,3-trisubstituted allenes by Schomaker and co-workers in 2017. Using BisDiazaphos ligand, the reaction was performed regioselectively on the terminal carbon of the allene under 10 bars of CO/H2 (1:1).…”