Chiral N,N Ligands Enabling Palladium‐Catalyzed Enantioselective Intramolecular Heck–Matsuda Carbonylation Reactions by Sequential Migratory and CO Insertions

Abstract

Unprecedented enantioselective intramolecular Heck carbonylation reactions of arenediazonium salts were enabled by a chiral N,N ligand. This reaction constitutes the first enantioselective Heck carbonylation that proceeds through migratory insertion followed by CO insertion. The enantioenriched functionalized dihydrobenzofurans were obtained in good to high yields and enantiomeric ratios of up to 98:2 under mild and operationally simple reaction conditions.

Ruthenium(II)‐Catalyzed Asymmetric Inert C−H Bond Activation Assisted by a Chiral Transient Directing Group

“…However, construction of this structural motif, as well as its associated enantiocontrol, is highly challenging . Recently, some elegant progress has been achieved by transition‐metal‐catalyzed asymmetric intramolecular annulations with various pre‐activated substrates, such as olefin‐tethered aryl halides, diazonium salts, and boronic reagents (Scheme a). Intriguingly, the analogous asymmetric annulations have been realized by the directing‐group‐assisted C−H activation promoted by either a rhodium(I) or rhodium(III) catalyst (Scheme b) .…”

Enantioselective Synthesis of 2‐Oxindole Spirofused Lactones and Lactams by Heck/Carbonylative Cylization Sequences: Method Development and Applications

“…However, an enantioselective version of this process to give carbonyl compounds with a quaternary stereocenter is surprisingly scarce . Recently, Correia and co‐workers reported the first successful asymmetric Heck carbonylative Suzuki coupling and esterification reaction enabled by a chiral N,N ligand to deliver dihydrobenzofurans, containing either ketone‐ or ester‐substituted quaternary carbon centers, in up to 96 % ee . We envisaged that either lactonization or lactamization would take place after Pd‐assisted CO insertion when an alkenyl substrate with an embedded oxygen‐ or nitrogen‐based nucleophile is used (Scheme d).…”

Enantioselective Heck Arylation of Acyclic Alkenol Aryl Ethers: Synthetic Applications and DFT Investigation of the Stereoselectivity

“…In particular, Heck arylations have been instrumental in the synthesis of valuable novel materials, including new medicines and fine chemicals, constituting the activity of intense research interest worldwide. [1][2][3][4][5] Recent developments in the enantioselective Heck arylations have focused mostly on the use of chiral bisphosphine monoxides (BPMO), [6] P,Nligands, N,N-ligands, [7] and phase-transfer chiral counterions, [8,9] although the popular bidentate phosphines are still commonplace. [10,11] Additionally, the introduction of selectivity-inducing strategies, such as the use of redox relay, [12][13][14][15][16][17][18][19][20][21][22][23][24][25] and directing groups have also greatly improved and extended the scope of this reaction.…”