Xiao Zheng

Name: 郑啸; Xiao Zheng

Organization: Xiamen University

Department: Department of Chemistry and The Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, and Department of Pharmaceutical Sciences, Medical College

Title: Associate Professor

Chemicals
References

SmI2-Mediated Radical Coupling Strategy to Securinega Alkaloids: Total Synthesis of (−)-14,15-Dihydrosecurinine and Formal Total Synthesis of (−)-Securinine

Co-reporter:Xiao Zheng, Juan Liu, Chen-Xi Ye, Ao Wang, Ai-E Wang, and Pei-Qiang Huang

The Journal of Organic Chemistry 2015 Volume 80(Issue 2) pp:1034-1041

Publication Date(Web):December 15, 2014

DOI:10.1021/jo502522x

The asymmetric total synthesis of (−)-14,15-dihydrosecurinine and the formal total synthesis of (−)-securinine were accomplished starting from an easily available malimide. A concise SmI2-mediated radical coupling strategy has been developed to construct the bridged α-hydroxy 6-azabicyclo[3.2.1]octanone in four steps with high diastereoselectivity.

Titanocene(III)-Catalyzed Three-Component Reaction of Secondary Amides, Aldehydes, and Electrophilic Alkenes

Co-reporter:Dr. Xiao Zheng;Jiang He;Heng-Hui Li;Ao Wang;Xi-Jie Dai;Dr. Ai-E Wang; Pei-Qiang Huang

Angewandte Chemie International Edition 2015 Volume 54( Issue 46) pp:13739-13742

Publication Date(Web):

DOI:10.1002/anie.201506907

Abstract

An umpolung Mannich-type reaction of secondary amides, aliphatic aldehydes, and electrophilic alkenes has been disclosed. This reaction features the one-pot formation of CN and CC bonds by a titanocene-catalyzed radical coupling of the condensation products, from secondary amides and aldehydes, with electrophilic alkenes. N-substituted γ-amido-acid derivatives and γ-amido ketones can be efficiently prepared by the current method. Extension to the reaction between ketoamides and electrophilic alkenes allows rapid assembly of piperidine skeletons with α-amino quaternary carbon centers. Its synthetic utility has been demonstrated by a facile construction of the tricyclic core of marine alkaloids such as cylindricine C and polycitorol A.

Titanocene(III)-Catalyzed Three-Component Reaction of Secondary Amides, Aldehydes, and Electrophilic Alkenes

Co-reporter:Dr. Xiao Zheng;Jiang He;Heng-Hui Li;Ao Wang;Xi-Jie Dai;Dr. Ai-E Wang; Pei-Qiang Huang

Angewandte Chemie 2015 Volume 127( Issue 46) pp:13943-13946

Publication Date(Web):

DOI:10.1002/ange.201506907

Abstract

Umpolung of Hemiaminals: Titanocene-Catalyzed Dehydroxylative Radical Coupling Reactions with Activated Alkenes

Co-reporter:Assoc.Dr. Xiao Zheng;Xi-Jie Dai;Hong-Qiu Yuan;Chen-Xi Ye;Jie Ma; Pei-Qiang Huang

Angewandte Chemie International Edition 2013 Volume 52( Issue 12) pp:3494-3498

Publication Date(Web):

DOI:10.1002/anie.201210088

Umpolung of Hemiaminals: Titanocene-Catalyzed Dehydroxylative Radical Coupling Reactions with Activated Alkenes

Co-reporter:Assoc.Dr. Xiao Zheng;Xi-Jie Dai;Hong-Qiu Yuan;Chen-Xi Ye;Jie Ma; Pei-Qiang Huang

Angewandte Chemie 2013 Volume 125( Issue 12) pp:3578-3582

Publication Date(Web):

DOI:10.1002/ange.201210088

SmI2-Mediated Radical Cross-Couplings of α-Hydroxylated Aza-hemiacetals and N,S-Acetals with α,β-Unsaturated Compounds: Asymmetric Synthesis of (+)-Hyacinthacine A2, (−)-Uniflorine A, and (+)-7-epi-Casuarine

Co-reporter:Xue-Kui Liu, Shi Qiu, Yong-Gang Xiang, Yuan-Ping Ruan, Xiao Zheng, and Pei-Qiang Huang

The Journal of Organic Chemistry 2011 Volume 76(Issue 12) pp:4952-4963

Publication Date(Web):May 16, 2011

DOI:10.1021/jo200600n

The SmI2-mediated radical coupling reactions of β-hydroxylated pyrrolidine/piperidine aza-hemiacetals 8 and 9 and N,S-acetals 6 and 33 with α,β-unsaturated compounds are described. This method allows a rapid access to β-hydroxylated pyrrolidines, piperidines, pyrrolizidinones, and indolizidinones. Starting from N,S-acetal 33 and via a common intermediate 27, the alkaloids hyacinthacine A2 (2), uniflorine A (3, 6-epi-casuarine), and the unnatural epimer 7-epi-casuarine (37) have been synthesized in four and five steps with overall yields of 34%, 16%, and 13%, respectively. The radical mechanism of the coupling reactions has been confirmed by controlled experiments, which also allowed deducing the anionic mechanism in the coupling between N,S-acetal 6 and carbonyl compounds. This demonstrates that the mechanisms of these SmI2-mediated reactions are switchable from Barbier-type anionic to radical by cooperative action of BF3·OEt2 and t-BuOH.

One-pot cross-coupling of N-acyl N,O-acetals with α,β-unsaturated compounds

Co-reporter:Yong-Gang Xiang, Xiang-Wu Wang, Xiao Zheng, Yuan-Ping Ruan and Pei-Qiang Huang

Chemical Communications 2009 (Issue 45) pp:7045-7047

Publication Date(Web):13 Oct 2009

DOI:10.1039/B915488D

The synergistic action of BF3·OEt2 and SmI2 allowed a series of intermolecular cross-couplings of readily available N-acyl N,O-acetals with α,β-unsaturated compounds to be performed in high yields, which was applied to the stereoselective synthesis of pyrrolizidine alkaloid (+)-xenovenine.

Generation and α-hydroxyalkylation of a novel 3-piperidinol N-α-carbanion intermediate

Co-reporter:Xiao Zheng;Guo Chen;YuanPing Ruan;PeiQiang Huang

Science China Chemistry 2009 Volume 52( Issue 10) pp:1631-1638

Publication Date(Web):2009 October

DOI:10.1007/s11426-009-0229-2

The (S)-sulfide 6 has been synthesized as a synthetic equivalent of novel 3-piperidinol N-α-carbanion B via deprotonation and lithium naphthanelide (LN)-mediated reductive lithiation. The reaction of the 3-piperidinol N-α-carbanion intermediate B with carbonyl compounds gave, besides some reduced product 2a, the desired α-hydroxyalkylation products 12–17 with excellent 2,3-diastereoselectivity. The reductive α-hydroxyalkylation with unsymmetric carbonyl compounds led to only 50:50 to 77:23 diastereoselectivities at the C-1′ carbinol center.

One-pot cross-coupling of N-acyl N,O-acetals with α,β-unsaturated compounds

Co-reporter:Yong-Gang Xiang, Xiang-Wu Wang, Xiao Zheng, Yuan-Ping Ruan and Pei-Qiang Huang

Chemical Communications 2009(Issue 45) pp:NaN7047-7047

Publication Date(Web):2009/10/13

DOI:10.1039/B915488D