<scp>DMAP‐Catalyzed</scp>
C—N Bond Formation for Diverse Synthesis of Imidazo[1,2‐
<i>a</i>
]pyrimidine and Pyrimido[1,2‐
<i>a</i>
]benzimidazole Derivatives
作者:Le‐Le Shang、Yun Feng、Xing‐Lian Gao、Zi‐Ren Chen、Yu Xia、Wei‐Wei Jin、Chen‐Jiang Liu
DOI:10.1002/cjoc.202000214
日期:2020.12
A DMAP (2‐dimethylaminopyridine)‐catalyzed condensation reactions for the successful direct construction of pyrimido[1,2‐a]benzimidazole or imidazo[1,2‐a]pyrimidine has been developed. The method utilizes readily available α‐bromocinnamaldehydes with 2‐aminobenzimidazole or 2‐aminoimidazole as starting materials in the presence of 2‐DMAP/TBHP. In the process, two C—N bonds were successfully constructed
N-Heterocyclic Carbene-Catalyzed Enantioselective Synthesis of Spiro-glutarimides via α,β-Unsaturated Acylazoliums
作者:Santigopal Mondal、Arghya Ghosh、Subrata Mukherjee、Akkattu T. Biju
DOI:10.1021/acs.orglett.8b01799
日期:2018.8.3
NHC-catalyzed enantioselective [3 + 3] spiro-annulation of α,β-unsaturated aldehydes with cyclic β-ketoamides allowing the preparation of synthetically and biologically important spiro-glutarimide derivatives has been reported. The interception of the ketoamides with catalytically generated chiral α,β-unsaturatedacylazoliums proceeds in a Michael addition–intramolecular amidation pathway to deliver
NHC-Catalyzed [3 + 3] Annulation of Thioamides and Modified Enals for the Enantioselective Synthesis of Functionalized Thiazinones
作者:Arghya Ghosh、Soumen Barik、Akkattu T. Biju
DOI:10.1021/acs.orglett.9b03188
日期:2019.11.1
(NHC)-catalyzed [3 + 3] annulation of thioamides with modified enals allowing the enantioselective synthesis of functionalized 1,3-thiazin-4-ones is reported. The NHC generated from the chiral triazolium salt was optimal and the reaction is initiated by the thia-Michael addition to catalytically generated α,β-unsaturated acylazolium intermediates derived from 2-bromoenals, followed by intramolecular cyclization
The highly diastereoselectivesynthesis of CF3-containing vicinal diamines by a convenient two-step procedure without the need to isolate the intermediate products is described.
描述了通过不需分离中间产物的方便的两步法高度非对映选择性地合成含CF 3的邻位二胺。
Enantioselective Synthesis of Tricyclic β-Lactones by NHC-Catalyzed Desymmetrization of Cyclic 1,3-Diketones
作者:Sayan Shee、Subrata Mukherjee、Rajesh G. Gonnade、Akkattu T. Biju
DOI:10.1021/acs.orglett.0c01756
日期:2020.7.17
The NHC-catalyzed desymmetrization of cyclic-1,3-diketones allowing the enantioselective construction of tricyclic β-lactones with five contiguous stereocenters, including two quaternary stereocenters, has been developed. The mild and operationally simple addition of α-bromoenals to cyclopentane-1,3-diketone derivatives proceeds via the initial formation of chiral α,β-unsaturated acylazolium intermediates