401636-52-0Relevant academic research and scientific papers
Visible-Light-Promoted Biomimetic Reductive Functionalization of Quaternary Benzophenanthridine Alkaloids
Cheng, Pi,Liu, Wei,Liu, Yisong,Reiser, Oliver,Wang, Lin,Wang, Wei,Wang, Xinhao,Xie, Hongqi,Zeng, Jianguo
, p. 2390 - 2397 (2021/08/20)
Reduction of an iminium C=N double bond is the most important phase I metabolism process associated with the cytotoxic property of quaternary benzophenanthridine alkaloids (QBAs). Inspired by the light-mediated reduction of QBAs with nicotinamide adenine dinucleotide, a visible-light-promoted reductive functionalization reaction of QBAs is reported in this study. C4-Alkyl-1,4-dihydropyridines (DHPs) enable the direct reductive alkylation of QBA independently, serving as both single-electron-transfer reductant reagents under irradiation with 455 nm blue light in the absence of photocatalysts and additional additives. Our protocol can be further applied to the semisynthesis of natural 6-substituted dihydrobenzophenanthridine derivatives such as O-acetyl maclekarpine E.
Photocatalytic Three-Component Umpolung Synthesis of 1,3-Diamines
Rossolini, Thomas,Leitch, Jamie A.,Grainger, Rachel,Dixon, Darren J.
supporting information, p. 6794 - 6798 (2018/10/24)
A visible-light-mediated photocatalytic umpolung synthesis of 1,3-diamines from in situ-generated imines and dehydroalanine derivatives is described. Pivoting on a key nucleophilic addition of photocatalytically generated α-amino radicals to electron-deficient alkenes, this three-component coupling reaction affords 1,3-diamines efficiently and diastereoselectively. The mild protocol tolerates a wide variety of functionalities including heterocycles, pinacol boronates, and aliphatic chains. Application to biologically relevant α-amino-γ-lactam synthesis and extension to 1,3-aminoalcohols is also demonstrated.
Substituted Hantzsch Esters as Versatile Radical Reservoirs in Photoredox Reactions
Gu, Fangjun,Huang, Wenhao,Liu, Xu,Chen, Wenxin,Cheng, Xu
supporting information, p. 925 - 931 (2018/01/04)
Substituted Hantzsch esters can act as radical reservoirs in photoredox reactions, steadily releasing a carbon radical and a hydrogen atom radical in the absence of an additional electron acceptor. We propose that radical release by substituted Hantzsch esters occurs via a mechanism involving an internal redox cycle. Cinnamidecinnamides, styrenes, α,β-unsaturated acids, and diarylethenes could be alkylated smoothly with these reagents. (Figure presented.).
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
Chen, Wenxin,Liu, Zheng,Tian, Jiaqi,Li, Jin,Ma, Jing,Cheng, Xu,Li, Guigen
supporting information, p. 12312 - 12315 (2016/10/07)
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h-1 turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry was used to synthesize a common precursor of a class of hydroxysteroid dehydrogenase inhibitors.
Alkyl transfer from C-C cleavage
Li, Guangxun,Chen, Rong,Wu, Lei,Fu, Qingquan,Zhang, Xiaomei,Tang, Zhuo
supporting information, p. 8432 - 8436 (2013/09/02)
Hydrogenation was only the beginning: Hantzsch esters have now been used to transfer alkyl groups to imines under mild catalytic conditions to provide a variety of amines (see scheme). Benzyl, secondary alkyl, and tertiary alkyl groups containing ether, ester, and hydroxy functionalities were transferred successfully. The use of Hantzsch esters as alkylation reagents offers a practical and complementary alternative to organometallic processes. Copyright
