Carbene-catalyzed LUMO activation of alkyne esters for access to functional pyridines
作者:Chengli Mou、Jichang Wu、Zhijian Huang、Jun Sun、Zhichao Jin、Yonggui Robin Chi
DOI:10.1039/c7cc08039e
日期:——
A carbene-catalyzed LUMOactivation of α,β-unsaturated alkyne esters is reported. This catalytic process allows for effective reactions of alkyne esters with enamides to synthesize functional pyridines via simple protocols. A previously unexplored unsaturated alkyne acyl azolium intermediate is involved in the key step of the reaction.
Esters as Alkynyl Acyl Ammonium and Azolium Precursors: A Formal [2 + 3] Annulation with Amidomalonates via Lewis Base/Lewis Acid Cooperative Catalysis
作者:Jing Cao、Kewen Sun、Shuding Dong、Tao Lu、Ying Dong、Ding Du
DOI:10.1021/acs.orglett.7b03453
日期:2017.12.15
Esters are for the first time used as α,β-unsaturated alkynyl acyl ammonium and azolium precursors to undergo a formal [2 + 3] annulation with amidomalonates through DMAP/LiCl or carbene/LiCl cooperative catalysis. A wide range of (Z)-5-amino-3-furanones were obtained in moderate to high yields with high regioselectivity and stereoselectivity. In addition, a plausible mechanism based on the calculated
Construction of Functionalized 2<i>H</i>-Pyran-2-ones via N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of Alkynyl Esters with Enolizable Ketones
作者:Zheng Liang、Jibin Li、Lei Wang、Zexuan Wei、Jiahui Huang、Xinrui Wang、Ding Du
DOI:10.1021/acs.joc.2c02392
日期:2023.2.3
A new synthesis of functionalized 2H-pyran-2-ones has been developed through N-heterocyclic carbene-catalyzed formal [3 + 3] annulation of alkynyl esters with enolizable ketones. The key to the success of this protocol relies on the use of an NHC instead of a tertiaryamine as the catalyst. This protocol also features a broad substrate scope and mildmetal-free conditions, offering simple and rapid
The present invention provides processes for the preparation of Acalabrutinib (1), as well as intermediates useful in the preparation thereof. In particular, processes are provided for coupling of a compound of Formula (5) and 2-butynoic acid in the presence of Carbodiimide (8) to afford Acalabrutinib (1).