Intra‐Intermolecular Palladium‐Catalyzed Domino Reactions of Glycine Allylamides for the Synthesis of Diversely Functionalized Piperazinones

Abstract

Easily accessible N-tosylglycine allylamides have been converted into diversely functionalized piperazinone derivatives by inter-intramolecular oxidative domino palladium-catalyzed reactions. Aminochlorination and aminoacetoxylation processes were achieved by employing CuCl2 and PhI(OAc)2 as the oxidizing agents to give 5-chloromethyl- and 5-acetoxymethyl-substituted piperazinones, respectively. Inter-intramolecular domino palladium-catalyzed reactions of N-tosylglycine allylamides were used to access piperazinones with functional groups that can undergo further transformations. Aminochlorination and aminoacetoxylation processes were achieved by using CuCl2 and PhI(OAc)2 as oxidizing agents to give 5-chloromethyl- and 5-acetoxymethyl-substituted piperazinones, respectively

(Diacyloxyiodo)benzenes‐Driven Palladium‐Catalyzed Cyclizations of Unsaturated N‐Sulfonylamides: Opportunities of Path Selection

“…No reaction occurred when working with CH 2 Cl 2 as solvent, either at room temperature or at reflux. However, on changing to DCE at reflux (conditions 1), we obtained the 5‐vinylpiperazinone 3b in 50% yield (Scheme , and Table , entry 1), instead of the anticipated corresponding aminoacetoxylated product . Performing the cyclization in MeCN at room temperature for 24 h also furnished the product, although in lower yield.…”

“…In this context, some of us recently described the intra‐intermolecular conversion of glycine allylamides into acetoxymethyl‐substituted piperazinones [Scheme , Eq. (1)] . In this contribution, we show that slight modifications of the substrate and/or the oxidizing system can trigger alternative mechanisms [Scheme , Eqs.…”

Intramolecular Oxidative Palladium-Catalyzed Amination Involving Double C–H Functionalization of Unactivated Olefins

“…26 In 2015, readily accessible N-arylsulfonylglycine allylamides 28 are fruitful starting material for aminoacetoxylation processes leading to 5-acetoxymethyl-and 5-hydroxymethyl-substituted piperazinones 29 (Scheme 17). 27 Higher yields were achieved by using stoichiometric NaOAc and Bu 4 NHSO 4 in addition to Pd(OAc) 2 as the catalyst and PhI(OAc) 2 as the oxidant. In this case, no cyclization products were observed in the absence of additive or base.…”

Hypervalent Iodine (III) Catalyzed Regio- and Diastereoselective Aminochlorination of Tailored Electron Deficient Olefins via GAP Chemistry

“…Several research groups have made great contributions in developing both intermolecular and intramolecular aminohalogenation (Minakata et al, 2006 ; Li et al, 2007 ; Michael et al, 2008 ; Chen et al, 2010 ; Denmark et al, 2012 ; Yin et al, 2012 ; Chemler and Bovino, 2013 ; Song et al, 2013 , 2016 ; Martínez and Muñiz, 2014 ; Broggini et al, 2015 ; Qin et al, 2015 ; Zhu et al, 2015 ; Legnani et al, 2018 ; Cai et al, 2019 ), in which a series of halogen/nitrogen sources, such as CFBSA (Pu et al, 2016 ), NCS/MeCN (Tay et al, 2013 ), NCP (Zhu et al, 2018 ), NFSI/TMSCl (Arteaga et al, 2018 ), TsNCl 2 (Han et al, 2007 ; Wu and Wang, 2008 ; Wei et al, 2009 ), TsNHCl (Cai et al, 2011 ), TsNNaCl (Martínez and Muñiz, 2014 ), 2-NsNNaCl (Li et al, 2001 ), or the combination of 2-NsNCl 2 and 2-NsNHNa (Liu et al, 2006 ), and so on, were employed for many types of alkene substrates. Most of these aminohalogenation systems take advantage of metals or organic catalysts to give good yields and excellent regioselectivities and diastereoselectivities.…”