N−H Imine as a Powerful Directing Group for Cobalt‐Catalyzed Olefin Hydroarylation
作者:Wengang Xu、Naohiko Yoshikai
DOI:10.1002/anie.201605877
日期:2016.10.4
N‐alkyl and N‐aryl imineshave been frequently used as directing groups in rhodium‐ and cobalt‐catalyzed hydroarylation reactions of olefins and alkynes. However, the scope of such hydroarylation reactions has been limited by the difficulty of preparation of sterically hindered imines by condensation, and also by the steric bulkiness of the iminegroup itself. Reported herein is that an N−H imine serves
Rhodium-Catalyzed Dynamic Kinetic Asymmetric Transformations of Racemic Allenes by the [3+2] Annulation of Aryl Ketimines
作者:Duc N. Tran、Nicolai Cramer
DOI:10.1002/anie.201304919
日期:2013.9.27
Racemization required: Rhodium(I)‐catalyzed CH activation directed by unprotected ketimines initiates selective [3+2] cycloaddition with allenes, providing access to highly substituted indenylamines. The reaction proceeds through the dynamic kinetic asymmetric transformation of racemic allenes. The catalyst controls the enantio‐ and diastereoselectivity, the regioselectivities of the CH activation and allene
Tertiary Carbinamine Synthesis by Rhodium-Catalyzed [3+2] Annulation of N-Unsubstituted Aromatic Ketimines and Alkynes
作者:Zhong-Ming Sun、Shuo-Ping Chen、Pinjing Zhao
DOI:10.1002/chem.200902814
日期:2010.2.22
A convenient and waste‐free synthesis of indene‐based tertiary carbinamines by rhodium‐catalyzed imine/alkyne [3+2] annulation is described. Under the optimized conditions of 0.5–2.5 mol % [(cod)Rh(OH)}2] (cod=1,5‐cyclooctadiene) catalyst, 1,3‐bis(diphenylphosphanyl)propane (DPPP) ligand, in toluene at 120 °C, N‐unsubstituted aromatic ketimines and internal alkynes were coupled in a 1:1 ratio to form