1011484-23-3Relevant articles and documents
Constructing Saturated Guanidinum Heterocycles by Cycloaddition of N-Amidinyliminium Ions with Indoles
Allred, Tyler K.,Shaghafi, Michael B.,Chen, Pan-Pan,Tran, Quan,Houk,Overman, Larry E.
supporting information, p. 7618 - 7623 (2021/10/12)
We report that structurally complex guanidinium heterocycles can be prepared in one step by regio- and stereoselective [4 + 2]-cycloadditions of N-amidinyliminium ions with indoles or benzothiophene. In contrast to reactions of these heterodienes with alkenes, density functional theory (DFT) calculations show that these cycloadditions take place in a concerted asynchronous fashion. The [4 + 2]-cycloaddition of N-amidinyliminium ions (1,3-diaza-1,3-dienes) with indoles and benzothiophene are distinctive, as related [4 + 2]-cycloadditions of N-acyliminium ions (1-oxa-3-aza-1,3-dienes) are apparently unknown.
N-Alkylation-Initiated Redox-Neutral [5 + 2] Annulation of 3-Alkylindoles with o-Aminobenzaldehydes: Access to Indole-1,2-Fused 1,4-Benzodiazepines
Wang, Shuai,Shen, Yao-Bin,Li, Long-Fei,Qiu, Bin,Yu, Liping,Liu, Qing,Xiao, Jian
, p. 8904 - 8908 (2019/11/19)
Described herein is an unprecedented N-Alkylation-initiated redox-neutral [5 + 2] annulation of 3-Alkylindoles with o-Aminobenzaldehydes via a cascade N-Alkylation/dehydration/[1,5]-hydride transfer/Friedel-Crafts alkylation sequence. A series of indole-1,2-fused 1,4-benzodiazepines are facilely constructed in moderate to good yields in one step. This protocol features excellent regioselectivity, metal-free conditions, high step economy, and wide substrate scope.
Methylation of C(sp3)-H/C(sp2)-H bonds with methanol catalyzed by cobalt system
Liu, Zhenghui,Yang, Zhenzhen,Yu, Xiaoxiao,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Liu, Zhimin
supporting information, p. 5228 - 5231 (2017/11/06)
A highly efficient Co-based catalytic system, composed of a commercially available Co salt, a tetradentate phosphine ligand P-(CH2CH2PPh2)3(PP3), and a base (denoted as [Co]/PP3/base), is developed for the methylation of C(sp3)-H and C(sp2)-H bonds using methanol as a methylating reagent. The Co(BF4)2.6H2O/PP3/K2CO3 catalytic system showed high catalytic activity for the methylation of C-H bonds in aryl alkyl ketones, aryl acetonitriles, and indoles, with wide substrate scope and good functional group tolerance, and methylsubstituted products were obtained in good to excellent yields at 100 °C. This cheap, readily available, and highly efficient Co-based catalytic system may have promising applications in methylation reaction using methanol.