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
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
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
Michael G. J. Doyle, Alexis L. Gabbey, Wesley McNutt, Rylan J. Lundgren
Summary: In this study, electron-deficient arylacetates were utilized as benzyl nucleophile surrogates to successfully generate enantioenriched acyclic molecules containing quaternary carbon centers via a two-step substitution-decarboxylation process. Products were often obtained with >90% ee using a commercially available catalyst.
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, Multidisciplinary
Yu-Qing Xiao, Miao-Miao Li, Zheng-Xin Zhou, Yu-Jie Li, Meng-Yue Cao, Xiao-Peng Liu, Hai-Hua Lu, Li Rao, Liang-Qiu Lu, Andre M. Beauchemin, Wen-Jing Xiao
Summary: This article describes a palladium-catalyzed highly diastereo- and enantioselective (3+2) cycloaddition reaction, which successfully synthesizes a variety of chiral five-membered heterocycles. The key to the success of this reaction is the remote stereoinduction through hydrogen bond, addressing the challenge of generating chiral quaternary stereocenters using substrates with two different acceptors.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
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)
Article
Chemistry, Organic
Oceane Flores, Patrick Wagner, Jean Suffert
Summary: Exploration of 4-exo-dig cyclocarbopalladation in the discovery of new and original scaffolds resulted in unexpected findings, including the identification of polycyclic molecules with a tetrasubstituted carbon. The presence of a triple bond substituting the cyclohexene ring on the starting compound was found to be crucial for high stereoselectivity. This observation was confirmed by the reaction of a nonsubstituted cyclohexene ring, which led to poor stereoselectivity and low yields.
Article
Chemistry, Organic
Roger Machin Rivera, Nikolas R. Burton, Luke D. Call, Marshall A. Tomat, Vincent N. G. Lindsay
Summary: This study reports a method for synthesizing particularly hindered tertiary alcohols via rearrangement reactions using [3,3]-sigmatropic rearrangements. Experimental studies suggest that the reaction proceeds through a close radical pair, leading to highly selective rearranged products.
Article
Chemistry, Applied
Michael Franc, Ivana Cisarova, Jan Vesely
Summary: Cooperative amino- and palladium catalysis utilizing heterocyclic systems with sulfur atoms remains underdeveloped. The enantioselective cyclization of enals with thiazole derivatives using achiral Pd(0) complexes and chiral secondary amines yielded chiral spirocyclic thiazolones with high yields and stereoselectivities. Furthermore, this strategy enables the access to highly substituted chiral cyclopentane derivatives through additional transformations of spirocyclic thiazolones.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Junqiang Wei, Vincent Gandon, Ye Zhu
Summary: Synthetic application of asymmetric catalysis requires strategic alignment of bond construction and chiral target molecule creation. Remote desymmetrization offers advantages in spatial decoupling of catalytic transformation and generation of stereogenic element. However, this spatial separation presents challenges for chiral catalysts to discriminate distant enantiotopic sites several bonds away from a prochirality center.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Xin-Wei Wang, Mu-Wang Chen, Bo Wu, Baomin Wang, Boshun Wan, Yong-Gui Zhou
Summary: A chiral phosphoric acid-catalyzed enantioselective synthesis of spiro[indoline-3,6'-indolo[1,2-c]quinazolin]-2-ones has been developed, affording spiro aminals with quaternary stereogenic centers with high enantioselectivities. The protocol could be expanded to pyrrole-derived spiro chiral aminals, obtaining high yields and excellent enantioselectivities.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Phillippa Cooper, Andrew G. Dalling, Elliot H. E. Farrar, Timothy P. Aldhous, Simon Grelaud, Eleanor Lester, Lyman J. Feron, Paul D. Kemmitt, Matthew N. Grayson, John F. Bower
Summary: The Ir-catalyzed alkene hydroarylation allows for the efficient synthesis of quaternary benzylic centers, and the structural features of the ligand play a crucial role in the reaction efficiency.
Article
Chemistry, Multidisciplinary
Sijing Xue, Alexander Lucht, Jordi Benet-Buchholz, Arjan W. Kleij
Summary: The challenging metal-catalyzed asymmetric synthesis of highly functional quaternary carbon centers using decarboxylative C(sp(3))-C(sp(3)) bond formation reactions has been successfully reported in this study. By activating a key substrate, a vinyl cyclic carbonate, both the requisite nucleophile and electrophile reaction partner were provided for the asymmetric cross-coupling process. Through extensive screening of reaction conditions, additives and catalyst precursors, a protocol was developed that allowed access to a series of compounds featuring densely functionalized, elusive quaternary carbon stereocenters in appreciable yield and with enantiomeric ratios (er's) of up to 90 : 10.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
