952686-35-0Relevant articles and documents
Ternary Catalysis Enabled Three-Component Asymmetric Allylic Alkylation as a Concise Track to Chiral α,α-Disubstituted Ketones
Chang, Wenju,Fu, Xiang,Hu, Wenhao,Kang, Zhenghui,Liang, Yong,Tian, Xue,Xu, Xinfang,Zhao, Wenxuan
, p. 20818 - 20827 (2021/12/17)
Multicomponent reactions that involve interception of onium ylides through Aldol, Mannich, and Michael addition with corresponding bench-stable acceptors have demonstrated broad applications in synthetic chemistry. However, because of the high reactivity and transient survival of these in situ generated intermediates, the substitution-type interception process, especially the asymmetric catalytic version, remains hitherto unknown. Herein, a three-component asymmetric allylation of α-diazo carbonyl compounds with alcohols and allyl carbonates is disclosed by employing a ternary cooperative catalysis of achiral Pd-complex, Rh2(OAc)4, and chiral phosphoric acid CPA. This method represents the first example of three-component asymmetric allylic alkylation through an SN1-type trapping process, which involves a convergent assembly of two active intermediates, Pd-allyl species, and enol derived from onium ylides, providing an expeditious access to chiral α,α-disubstituted ketones in good to high yields with high to excellent enantioselectivity. Combined experimental and computational studies have shed light on the mechanism of this novel three-component reaction, including the critical role of Xantphos ligand and the origin of enantioselectivity.
Iridium-Catalyzed Propenylation Reactions for the Synthesis of 4-Pyridone Derivatives
Bai, Xue-dan,Wang, Jie,He, Ying
supporting information, p. 496 - 501 (2019/01/04)
Herein we report an iridium-catalyzed propenylation reaction of allylic carbonates with 4-hydroxypyridine derivatives. The process efficiently provides 4-pyridone derivatives with high stereoselectivities under mild conditions. The products could constitute valuable building blocks for the synthesis of natural products and other bioactive molecules. Preliminary mechanistic studies indicated that a tandem allylic substitution/isomerization reaction occurs to afford the propenylation products. (Figure presented.).