En Route to Enantioenriched Quaternary Stereocenters via Lewis Base/Palladium Cooperative Catalysis DOI Creative Commons

Maygan M. McGuire,

Andrew C. Bach,

Maren Pink

et al.

Helvetica Chimica Acta, Journal Year: 2024, Volume and Issue: 107(9)

Published: June 28, 2024

Abstract The prevalence of quaternary stereogenic centers in bioactive molecules coupled with innate challenges associated their enantioselective preparation continues to provide powerful impetus for the development catalytic asymmetric methods capable construction. Herein, we describe a cooperative isothiourea Lewis base‐palladium catalyst system that enables alkylation α‐substituted‐α‐cyano esters allyl methanesulfonate. While levels enantioselection are modest, this study represents first time have successfully constructed quaternary‐substituted using catalysis scheme. Further, strategy constitutes departure from ligand‐based enantiocontrol and suggests that, when acidic pro‐nucleophiles, protocols where base can outcompete direct deprotonation might be within reach.

Language: Английский

Cooperative Chiral Lewis Base/Palladium‐Catalyzed Asymmetric Syntheses of Methylene‐Containing δ‐Lactams DOI Creative Commons
Paul Zebrowski, Uwe Monkowius, Mario Waser

et al.

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(45)

Published: Oct. 19, 2023

We herein report a two-step approach for the enantioselective synthesis of novel chiral δ-lactams. By using cooperative ITU/achiral Pd-catalyst system, this protocol proceeds via an asymmetric α-allylation activated aryl esters first, followed by acid-mediated lactam formation. A variety differently substituted products could be obtained with usually high levels enantioselectivities and in reasonable yields (16 examples, up to 98 : 2 er 73 % yield over two steps). In addition, further utilizations transformations exocyclic double bond were successfully carried out as well.

Language: Английский

Citations

2
En Route to Enantioenriched Quaternary Stereocenters via Lewis Base/Palladium Cooperative Catalysis DOI Creative Commons

Maygan M. McGuire,

Andrew C. Bach,

Maren Pink

et al.

Helvetica Chimica Acta, Journal Year: 2024, Volume and Issue: 107(9)

Published: June 28, 2024

Abstract The prevalence of quaternary stereogenic centers in bioactive molecules coupled with innate challenges associated their enantioselective preparation continues to provide powerful impetus for the development catalytic asymmetric methods capable construction. Herein, we describe a cooperative isothiourea Lewis base‐palladium catalyst system that enables alkylation α‐substituted‐α‐cyano esters allyl methanesulfonate. While levels enantioselection are modest, this study represents first time have successfully constructed quaternary‐substituted using catalysis scheme. Further, strategy constitutes departure from ligand‐based enantiocontrol and suggests that, when acidic pro‐nucleophiles, protocols where base can outcompete direct deprotonation might be within reach.

Language: Английский

Citations

0