Rh(III)-Catalyzed C‚ÄìH Olefination Cascades to Divergently Construct Diverse Polyheterocycles by Tuning Manipulations of Directing Groups
Authors: Yong Wu
Ting Wang
Li Hai
Jian Chen
Dongxue Peng
Yuesen Shi
Ruizhi Lai
Xuexin Liu
Longyu Wang
Zhouping Wu
Hao Li
Xiaoyu Guo
Tianle Huang
Journal: Organic Letters (2021)
Discipline: CHEMISTRY
Keywords: divergent strategy; transition-metal-catalyzed C-H functionalization; complex scaffolds; Rh(III)-catalyzed; polyheterocycles
Affiliations: Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China

Abstract:  Inspired by the diversity created by nature, organic chemists have been using a divergent strategy to improve the synthetic efficiency of diverse molecules. Transition-metal-catalyzed C-H functionalization has become one of the most straightforward, powerful, and atom-economical methods to construct complex scaffolds. However, C-H activation initiated divergent transformation to prepare diverse molecules is still limited. To address this challenge, we herein developed Rh(III)-catalyzed C-H olefination/annulation reaction cascades to divergently construct diverse polyheterocycles by tuning manipulations of directing groups (DGs). Up to 9 distinct scaffolds were creatively synthesized under simple conditions with good functional group tolerance, chemo-, and regioselectivity. Such a versatile strategy and its extension may encourage researchers to discover more promising manipulations of DGs for transition-metal-catalyzed C-H bond activation, making diverse available targets and materials that would have been previously out of range. 

Retracted: No

PubPeer comments:
 Several 1H and 13C NMR spectra found in the supporting information file of this paper seem to have been manipulated with. Parts of the baseline of selected spectra are perfectly identical, see below: **3a** 13C spectrum: 15-22 = 31-39 ppm; 17-22 = 25-31 ppm; 58-64 = 64-71 ppm **3b** 13C spectrum: 34-39 = 65-70 ppm **3c** 13C spectrum: 12-18 = 20-26 ppm; 12-17 = 27-31 ppm; 12-15 = 32-35 = 35-38 ppm **3i** 13C spectrum: 47-50 = 28-32 = 32-36 ppm; 47-51 = 51-56 ppm **3l** 13C spectrum: 21-25 = 25-29 ppm; 29-31 = 34-37 ppm **3m** 13C spectrum: 22-27 = 27-31 ppm; 22-26 = 31-35 ppm; 32-35 = 35-38 ppm **3m** 1H spectrum: 0.6-1.2 = 1.2-1.75 = 2.2-2.75 = 3.4-3.9 ppm **3n** 13C spectrum: 9-17 = 40-48 ppm; 11-17 = 31-37 ppm; 11-14 = 25-28 ppm **3p** 13C spectrum: 4-9 = 9-15 = 20-25 = 28-34 = 40-46 ppm **4b** 1H spectrum: missing 13C satellites of DMSO-d5; no signal of H2O in the spectrum **4e** 13C spectrum: 58-65 = 49-57 ppm; 61-65 = 41-45 = 38-41 = 33-37 = 27-30 ppm; 58-61 = 21-25 ppm **5d** 1H spectrum: missing 13C satellites for the tert-butyl signal **6e** 13C spectrum: 20-27 = 27-34 ppm; 36-43 = 46-53 ppm The abovementioned aspects of the 1H and 13C NMR spectra were previously noticed in 3 other articles from the same group of authors and mentioned in the respective Pubpeer pages - [here] , [here] and [here] . The phenomenon remains unanswered. ,