Article
Chemistry, Physical
Peng Yan, Jia Zhang, Licheng Lu, Huayi Fang, Ping Lu
Summary: In this study, we report a new method for enantioselective Diels-Alder reaction catalyzed by a chiral catalyst COBI, which enables the asymmetric reaction of 2,3-disubstituted cyclobutenones with various dienes. This method successfully synthesizes bicyclo[4.2.0]octane derivatives with two contiguous angular quaternary centers, demonstrating intriguing structural patterns.
Article
Chemistry, Multidisciplinary
Manju Devi, Amol P. Jadhav, Ravi P. Singh
Summary: The stereoselective synthesis of 3,3'-disubstituted oxindoles with all-carbon quaternary stereocenters using KOH as a base has been achieved with an excellent diastereomeric ratio of 98:2. The practicality of the methodology has been demonstrated through the synthesis of a series of substrates with good to excellent yields. The aesthetic simplicity, accessibility, and eco-friendly nature of the base (KOH) have led to the broader application of this methodology in organic synthesis.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Wei Wang, Fangqing Zhang, Yangbin Liu, Xiaoming Feng
Summary: In this study, we report a novel method using a bimetallic catalyst for the asymmetric allylation of challenging trisubstituted allylic esters, achieving the construction of vicinal all-carbon quaternary stereocenters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xigong Liu, Changyin Zhao, Rongxiu Zhu, Lei Liu
Summary: The study presents a solution for constructing vicinal quaternary carbon stereocenters in acyclic systems, achieving excellent yields and selectivities through asymmetric cross-dehydrogenative coupling reactions. The generality of the approach was further demonstrated, and computational studies elucidated the origins of both diastereo- and enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Mayuko Isomura, David A. Petrone, Erick M. Carreira
Summary: A robust catalytic system utilizing chiral Ir-phosphoramidite and La(OTf)(3) enables highly enantioselective alkylation reactions of racemic tertiary alpha-allenyl alcohols with tetrasubstituted silyl ketene acetals. The reaction displays broad functional group tolerance and allows efficient generation of beta-allenyl ester products with excellent enantioselectivity, which can be further upgraded in structural complexity via stereoselective metal-catalyzed functionalization reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Jian Xu, Runze Li, Nian Xu, Xiaohua Liu, Fei Wang, Xiaoming Feng
Summary: The study describes the asymmetric catalytic synthesis of 3-cyclotrypt-amine substituted oxindoles with potential anticancer activity. This strategy allows for the quick assembly of cyclotryptamine subunits with two quaternary stereogenic centers in cis-selectivity.
Article
Chemistry, Multidisciplinary
Jordan J. Dotson, Ieva Liepuoniute, J. Logan Bachman, Vince M. Hipwell, Saeed Khan, K. N. Houk, Neil K. Garg, Miguel A. Garcia-Garibay
Summary: Solid-state photodecarbonylation is used to assemble vicinal quaternary stereocenter motif in bis(cyclotryptamine) alkaloids. The success of the reaction is influenced by the substrate conformation, which was studied experimentally and computationally leading to the successful synthesis of psychotriadine, a previously unidentified compound found in extracts of Psychotria colorata.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Ryo Tsuyusaki, Kosuke Nakashima, Yasuyuki Matsushima, Shin-ichi Hirashima, Tsuyoshi Miura
Summary: This study demonstrates the successful application of a thiourea organocatalyst in the direct construction of vicinal all-carbon quaternary stereocenters bearing a trifluoromethyl group. The reaction yields high amounts of spirooxindole derivatives with excellent enantioselectivities reaching up to 99% ee.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Sheng Zuo, Yuan Tao, Zhigang Liu, Ke Zhang, Luyun Zhang, Yingtang Ning, Fen-Er Chen
Summary: This study successfully synthesized highly congested indanone-based spirolactones through copper-catalyzed decarboxylative propargylation, with the key role of DPEN-based ligands. The method tolerated a wide range of functional groups, yielding high diastereo- and enantioselectivities. Mechanistic observations indicated the capability of the new copper complex to enable stereocontrolled addition to copper-allenylidene species.
Article
Chemistry, Multidisciplinary
Xianfu Shen, Tianfeng Peng, Fan Wang, Shumin Li, Xingfu Lei, Yunxiao, Wang, Feixiang Cheng, Teng Liu
Summary: This report presents the total synthesis of two bioactive HPI alkaloids, Flustramine B and Debromoflustramine B, achieved through a Cu-catalyzed cascade arylation-alkylation sequence as a key step. The overall yields of the compounds were 37.6% and 31.1% after 9 steps of synthesis.
Article
Chemistry, Multidisciplinary
Nicholas L. Magann, Erin Westley, Madison J. Sowden, Michael G. Gardiner, Michael S. Sherburn
Summary: The total synthesis of three diastereomeric matrine natural products is reported, which involved the formation of a tetracyclic framework using acyclic precursors and orchestrated intramolecular cycloadditions. The three natural products were obtained through late-stage hydrogenation and strain-release redox epimerizations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Jeremy Nugent, Alistair J. Sterling, Nils Frank, James J. Mousseau, Edward A. Anderson
Summary: Bicyclo[1.1.1]pentanes (BCPs) are synthesized efficiently using organophotoredox and hydrogen atom transfer catalysis, allowing for the preparation of alpha-quaternary BCPs. The products can be further transformed into a variety of useful derivatives, including enantioenriched BCPs.
Article
Chemistry, Organic
Shiyuan Kang, Yinxia Wu, Min Hu, Ying Ma, Xiangdi Huang, Zhen Hao, Xiujuan Li, Wen Chen, Hongbin Zhang
Summary: The asymmetric total synthesis of vinorine, a complex cage-like alkaloid, has been achieved using a flexible approach. Key steps in this synthesis involve a rearrangement/cyclization reaction to form the functional 9-azabicyclo[3.3.1]nonane scaffold, a high yield indole annulation to create a common intermediate for sarpagine-ajamaline type alkaloids, and a rearrangement reaction to construct the C15-C20 bond.
Article
Chemistry, Organic
Alexander J. Hughes, Steven D. Townsend
Summary: In this study, we achieved the gram-scale total synthesis of (+/-)-ibogamine in nine steps and with an overall yield of 24%. The key steps include a Mitsunobu fragment coupling and macrocyclic Friedel-Crafts alkylation to establish the nitrogen-containing core of ibogamine. Additionally, a regio- and diastereoselective hydroboration reaction was used to simultaneously form the tetrahydroazepine and isoquinuclidine ring systems via sulfonamide deprotection and intramolecular cyclization.
Article
Chemistry, Multidisciplinary
Weiping Zhou, Arnaud Voituriez
Summary: A cationic gold(I)-catalyzed asymmetric [3,3]-sigmatropic rearrangement of sulfonium leads to the formation of cyclopentenones with a C4-quaternary stereocenter after cyclization. This methodology was successfully applied to the efficient total synthesis of five natural sesquiterpenoids, demonstrating moderate to good yields and excellent enantiomeric excesses in 26 examples.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
