Expeditious synthesis of TADDOL-derived phosphoramidite and phosphonite ligands
摘要:
A simple and reliable protocol for the synthesis of TADDOL-derived monodentate ligands is reported. The reaction of the requisite TADDOL with PCl3 is immediately followed by the treatment of the crude intermediate with both nitrogen and carbon nucleophiles. Several previously unknown or difficult-to-make phosphoramidite and phosphonite ligands L1-L3 and L4-L9 were accessed using this novel procedure. (C) 2010 Elsevier Ltd. All rights reserved.
Anti‐headache chemistry: In the presence of a tailored modular P,P ligand the nickel‐catalyzed addition of HCN, generated in situ from TMS‐CN, to styrene derivatives proceeds with an unprecedented level of stereocontrol (up to 97 % ee) to give 2‐aryl‐acetonitriles, for example, the depicted precursor of Ibuprofen.
Highly Enantioselective Nickel-Catalyzed Hydrocyanation of Disubstituted Methylenecyclopropanes Enabled by TADDOL-based Diphosphite Ligands
作者:Rongrong Yu、Xianjie Fang
DOI:10.1021/acs.orglett.9b04374
日期:2020.1.17
A vast range of novel TADDOL-based diphosphite ligands were first synthesized and applied in the nickel-catalyzed asymmetric hydrocyanation of disubstituted methylenecyclopropanes. By employing these new catalysts, the conversion of diverse methylenecyclopropanes into their corresponding allylic nitriles was first enabled, in good yield with excellent enantioselectivities.
Enantioselective Nickel‐Catalyzed Migratory Hydrocyanation of Nonconjugated Dienes
作者:Rongrong Yu、Shanmugam Rajasekar、Xianjie Fang
DOI:10.1002/anie.202008854
日期:2020.11.23
Metal‐catalyzed chain‐walking reactions have recently emerged as a powerful strategy to functionalize remote positions in organic molecules. However, a chain‐walking protocol for nonconjugated dienes remains scarcely reported, and developments are currently ongoing. In this Communication, a nickel‐catalyzed asymmetric hydrocyanation of nonconjugated dienes involving a chain‐walking process is demonstrated
Nickel-Catalyzed Asymmetric Addition of Alkyne CH Bonds across 1,3-Dienes Using Taddol-Based Chiral Phosphoramidite Ligands
作者:Masamichi Shirakura、Michinori Suginome
DOI:10.1002/anie.201001188
日期:——
Enantioenriched 3‐methyl‐1,4‐enynes are the products of the title reaction. The terminal α‐siloxy‐sec‐alkyl groups were then converted into γ‐oxoalkyl groups by rhodium‐catalyzed conjugate alkynyl addition to α,β‐unsaturated ketones through cleavage of the alkynyl CC bond.
Regio-, Chemo-, and Enantioselective Ni-Catalyzed Hydrocyanation of 1,3-Dienes
作者:Rongrong Yu、Yidan Xing、Xianjie Fang
DOI:10.1021/acs.orglett.0c04133
日期:2021.2.5
A regio-, chemo-, and enantioselective nickel-catalyzed hydrocyanation of 1,3-dienes is reported. The key to the success of this asymmetric transformation is the use of a specific multichiral diphosphite ligand. In addition to aryl-substituted 1,3-dienes, highly challenging aliphatic 1,3-diene substrates can also be preferentially converted to the corresponding 1,2-adducts in decent yields with the