Article
Chemistry, Organic
Sajid Ur Rehman, Changkun Li
Summary: A highly regio- and enantioselective allylic sulfonation was achieved by using rhodium and bisoxazolinephosphine (NPN*) ligands, starting from racemic branched allylic carbonates and readily available sulfonylhydrazides under neutral conditions. The reaction produced branch-selective allylic sulfones with a >20:1 branch:linear ratio and >99% enantiomeric excess (ee) in <= 96% yield. Both Z and E linear allylic carbonates could also be transformed into the same chiral branched allylic sulfones with high regio- and enantioselectivities.
Article
Chemistry, Multidisciplinary
Guolin Wu, Yuan Yao, Gen Li, Xue Zhang, Hui Qian, Shengming Ma
Summary: This study developed a catalytic recipe of copper halides to address the issues of side reactions and selectivity in the 1,5-H transfer of alka-1,4-diyn-3-yl amines, providing various allenynes with excellent enantioselectivities. The method was successfully applied to the first highly enantioselective total synthesis of the natural product scorodonin. Mechanistic studies and DFT calculations elucidated the regioselectivity for the observed 1,5-H transfer.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Kai Ji, Ka Lu, Jie Huang, Zi-Hao Li, Hua Ke, Zhi-Min Chen
Summary: A Bronsted acid-catalyzed 1,4-addition hydrothiolation of branched 1,3-dienes was explored for the first time, along with a solvent-controlled divergent synthesis of sulfides. The study showed that the choice of solvent influenced the type of products obtained, with acetonitrile yielding allylic sulfides and dichloromethane yielding thiochromane derivatives. The regioselectivity of hydrothiolation was investigated using density functional theory calculations.
Article
Chemistry, Organic
Yujia Gao, Juan Zhang, Wenyu Shan, Weihong Fei, Jinzhong Yao, Weijun Yao
Summary: In this study, a trimerization reaction of gamma-aryl-3-butynoates was achieved through catalysis, leading to the formation of exocyclopentene derivatives with an allcarbon quaternary stereocenter. The reaction exhibited high stereoselectivity and enantioselectivity, delivering optically pure products with high enantiomeric excess values.
Article
Chemistry, Organic
Emanuele Azzi, Giovanni Ghigo, Lorenzo Sarasino, Stefano Parisotto, Riccardo Moro, Polyssena Renzi, Annamaria Deagostino
Summary: In this study, a photoinduced chloroamination cyclization of allenes was presented, resulting in the formation of 2-(1-chlorovinyl)pyrrolidines and related heterocycles. N-chlorosuccinimide (NCS) was used as the chlorine source. Detailed experimental and computational mechanistic studies revealed the formation of a common nitrogen centered radical (NCR) through multiple reaction pathways. The NCR then undergoes intramolecular cyclization and chlorination to yield the final product.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Srinivasarao Yaragorla, Dandugula Sneha Latha, Pallava Rajesh
Summary: The study introduced a simple and efficient One-Pot three-component reaction using tert-propargyl alcohols, primary amines, and acyl ketones to synthesize fully substituted pyrroles and pyridine derivatives. A green calcium catalyst was employed to facilitate the formation of β-amino allene intermediate, leading to fully substituted five and six-membered azacyclic compounds through subsequent hydroamination and deacylation reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sebastien Carret, Benjamin Darses, Soufiane Touil, Jean-Francois Poisson
Summary: A variety of 4-phosphinylpyrrolidin-3-ones were synthesized via a [3+2] cycloaddition reaction between aryl aldonitrones and phosphinylallenes. The products were obtained as unique 4,5-trans diastereomers in yields ranging from 47% to 80% for 23 examples. Chiral racemic allenes exhibited a moderate 2:1 to 4:1 2,5-diastereoselectivity. Under the reaction conditions, the cycloadducts undergo a rearrangement to selectively afford the corresponding pyrrolidin-3-ones. DFT calculations provided insights into the mechanism involving the homolytic cleavage of the N-O bond of the cycloadduct.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Yunlong Wei, Xinxin Wu, Yasu Chen, Chen Zhu
Summary: In this study, we have reported a novel intermolecular allenyl functionalization of alkenes through a radical-polar crossover process, leading to the synthesis of homoallenic alcohols and amides with high synthetic value. The key step of this reaction is the addition of an allenyl radical to an alkene, which is challenging due to the short lifetime of the allenyl radical and its tendency to form propargyl radicals. By strategically introducing a sulfone, the electrophilicity of the transient allenyl radicals can be efficiently improved, as supported by density functional theory calculations. Solvents act as nucleophiles in this radical-polar crossover, and the resulting products can be further converted into diverse complex molecules. This reaction proceeds under mild photoredox neutral conditions and exhibits exclusive regioselectivity, broad functionality tolerance, and high product diversity.
Article
Chemistry, Organic
Kui Liu, Gang Wang, Zhe-Wen Zhang, Yu-Yang Shi, Zhi-Shi Ye
Summary: This study documents an effective strategy for the ring-opening/elaboration of cyclopropanes using a phosphine catalyst, which produces 2,4-pentadiene sulfonamides and isoindolines in moderate to good yields. The key to the success of this reaction lies in the phosphine-catalyzed introduction of a trigonal center into cyclopropanes, resulting in the formation of a higher ring strain cyclopropylidenemethyl phosphonium salt. Furthermore, this methodology is utilized as a crucial step in the synthesis of bioactive molecules.
Article
Chemistry, Organic
Wen-Tao Li, Qiao Zhang, Meng-Yang Hu, Shou-Fei Zhu
Summary: In this study, a highly Markovnikov hydroalumination of aromatic terminal alkenes was achieved using a well-defined 2,9-diaryl-1,10-phenanthroline modified iron catalyst and commercially available DIBAL-H as the aluminum hydride reagent. Various new benzylaluminum complexes were prepared. This is the first iron-catalyzed alkene hydroalumination, and the regioselectivity observed is different from previous reports in the literature.
Article
Chemistry, Multidisciplinary
Yuichi Kobayashi, Yuji Takashima, Yuuya Motoyama, Yukari Isogawa, Kyosuke Katagiri, Atsuki Tsuboi, Narihito Ogawa
Summary: This study investigated the regioselectivity and enantiospecificity of substitution reactions of secondary propargylic alcohol derivatives using reagents derived from ArMgBr and Cu salts. The results showed that under certain reaction conditions, highly selective products could be obtained.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Bo-Han Zhu, Sheng-Bing Ye, Min-Ling Nie, Zhong-Yang Xie, Yi-Bo Wang, Peng-Cheng Qian, Qing Sun, Long-Wu Ye, Long Li
Summary: In this study, an unprecedented I-2-catalyzed cycloisomerization of ynamides is developed, leading to the synthesis of various functionalized bis(indole) derivatives in good to excellent yields. This reaction represents the first molecular-iodine-catalyzed tandem complex alkyne cycloisomerizations and a chemoselective cycloisomerization of tryptamine-ynamides involving distinct C(sp(3))-C(sp(3)) bond cleavage and rearrangement. Chiral tetrahydropyridine frameworks containing two stereocenters are also obtained with moderate to excellent diastereoselectivities and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hiroki Tashiro, Masahiro Terada, Itaru Nakamura
Summary: Gold-catalyzed reactions were used to synthesize 2H-azirines with sulfenyl and acyl groups at the 3-position, yielding good to excellent results. These reactions involved internal transfer of sulfinyl oxygen atom and carbene insertion into the N-S bond for ring construction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ryota Sakamoto, Minami Odagi, Masahiro Yamanaka, Kazuo Nagasawa
Summary: We report a 1,3-boron shift-type reaction occurring at the center (sp) carbon in allenes to generate 2-boryl-1,3-dienes with diverse substituents. Notably, this reaction takes place in situ with allenylboronates in the presence of carbamate and a small excess of sec-BuLi, eliminating the need for isolating the unstable homoallenylboronates.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Xiao-Qian Zhang, Congdi Zhang, Zhiyou Hu, Youliang Wang
Summary: The gold-catalyzed divergent additions of trans-2-butene-1,4-amino alcohols' N-H and O-H groups to alkynes, followed by a cascade (Aza-) Claisen rearrangement/cyclization sequence, has been reported. This reaction produces functionalized dihydropyrrole and dihydrofuran products.
Article
Chemistry, Applied
Irene Martin, Cristina Aragoncillo, Pedro Almendros
Summary: This research has achieved a selective palladium-catalyzed reaction sequence, leading to the synthesis of novel 2-iodo-1-aryl-9H-carbazoles. The observed formation of 2-iodocarbazoles in contrast to gold catalysis suggests a metal-controlled cyclization through chemo- and regioselective alkyl migration and iodonium migration.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Review
Chemistry, Multidisciplinary
Jose M. Alonso, Pedro Almendros
Summary: The allene functionality, specifically the allenol, has evolved from a chemical curiosity to a common building block in modern organic chemistry, with unique reactivity and frequent occurrence in naturally systems. This Review highlights the significant contributions to the chemistry of allenols in the past decade, focusing on their synthesis, reactivity, and presence in natural products.
Article
Chemistry, Organic
Carlos Lazaro-Milla, Hikaru Yanai, Pedro Almendros
Summary: A new sequential cyclization cascade method has been successfully developed in this study for the efficient preparation of functionalized tricyclic indoline cores bearing two contiguous stereocenters.
Article
Chemistry, Applied
Ines Manjon-Mata, M. Teresa Quiros, Elena Velasco-Juarez, Elena Bunuel, Diego J. Cardenas
Summary: A diastereoselective synthesis of borylated bicyclic 5-5 fused ring systems has been achieved through a domino Ni-catalyzed hydroborylative polycyclization of allenynes, providing two new C-C bonds and one C-B bond. The reaction is atom-economical, rapid, and tolerant to functional groups. The process involves oxidative cyclometallation, sigma-metathesis, and 1,2-insertion into the Ni-H bond, followed by reductive elimination.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Irene Martin-Mejias, A. Sonia Petcu, Jose M. Alonso, Cristina Aragoncillo, Pedro Almendros
Summary: The controlled access to 1-aryl 2,3-diiodo-carbazoles involving iodine transposition has been achieved directly from acyclic precursors. The 2,3-diiodo-carbazole core is susceptible to further chemoselective decoration at C3-I or double difunctionalization.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Physical
Mireia Toledano-Pinedo, Teresa Martinez del Campo, Hikaru Yanai, Pedro Almendros
Summary: This study presents a gold-catalyzed bis[(trifluoromethyl)sulfonyl]ethylation of alpha-allenols, allowing the synthesis of sterically congested bis(triflyl)enals with quaternary carbon centers. The reaction pathway is different from the conventional approach, as Au(I) acts as a pi-Lewis base catalyst instead of a pi-Lewis acid, activating the allene and facilitating the unusual addition of a carbon nucleophile from the gold complex belonging to the allenol moiety. Density functional theory calculations were performed to understand this unique pathway.
Review
Chemistry, Applied
Jose M. Alonso, Pedro Almendros
Summary: Conjugated and non-conjugated allenones are widely used in organic synthesis, natural products, and mechanistic investigations due to their unique properties and applications. Their ability to form cycles allows for the preparation of strained systems, medium-sized rings, arenes, heterocycles, and complex polycycles. This comprehensive review provides an overview of the synthetic possibilities offered by allenones, inspiring the organic chemistry community in their search for more efficient synthetic methodologies, preparation of biological and pharmaceutical targets, and advancing theoretical organic chemistry knowledge. The review also discusses synthetic aspects, catalysis innovation, and mechanistic insights related to the allenone motif, as well as examples of total synthesis and pharmacologically active compounds. It aims to attract researchers from various fields including organic chemistry, synthetic chemistry, catalysis, theoretical chemistry, natural products, and medicinal chemistry.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
A. Sonia Petcu, Carlos Lazaro-Milla, F. Javier Rodriguez, Isabel Iriepa, Oscar M. Bautista-Aguilera, Cristina Aragoncillo, Jose M. Alonso, Pedro Almendros
Summary: Here, a convenient preparation method for isocoumarin and isoquinolone is described, which involves an initial bis(triflyl)ethylation reaction followed by heterocyclization. The efficiency of the reaction depends on the substituents' electronic nature in the precursors. Molecular docking of the obtained isocoumarins showed promising biological activities on human acetylcholinesterase.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Diego G. Matesanz, Laura Gamarra, Teresa Martinez del Campo, Pedro Almendros, Sara Cembellin
Summary: A highly selective Mn(I)-catalyzed dienylation of arenes and heteroarenes with acetylated allenes is reported. The method proceeds through a one-pot procedure and delivers linear 1,3-dienes as single products with high stereoselectivity and total regioselectivity. This strategy shows wide functional group tolerance and preparative scale utility, making it efficient for late-stage functionalization of complex valuable molecules. The synthetic importance is highlighted by different derivatizations of the final products, which can exhibit interesting fluorescence properties.
Article
Chemistry, Organic
Hikaru Yanai, M. Rosa Marquez, Sara Cembellin, Teresa Martinez del Campo, Pedro Almendros
Summary: An indium-promoted lactonization of (indol-3-yl)-2-oxoacetaldehydes, allowing the synthesis of substituted gamma-methylenebutenolides in water, has been achieved. This process differs from the established reactivity of unsaturated organic halides and carbonyls mediated by metals. The use of water as a medium and the ease of purification make this protocol a convenient and sustainable synthetic strategy. A plausible reaction pathway has been proposed with the aid of density functional theory calculations.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
M. Soledad Garre, Guillermo G. Otarola, Estibaliz Merino, David Sucunza, Enrique Aguilar, M. Teresa Quiros, Juan J. Vaquero, Patricia Garcia-Garcia
Summary: Cyclobutane-fused dihydropyridones can be synthesized efficiently via a completely endo-selective gold-catalyzed cyclization of alkynylcyclobutanes with an appended amide, under mild conditions. The observed selectivity, opposite to that observed for the cyclization of related alcohols and acids, is supported by DFT calculations.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Physical
Mireia Toledano-Pinedo, Teresa Martinez del Campo, Hikaru Yanai, Pedro Almendros
Summary: The gold-catalyzed bis[(trifluoromethyl)sulfonyl]ethylation of alpha-allenols, allowing the synthesis of sterically congested bis(triflyl)enals with quaternary carbon centers, is presented. In this reaction, a unique pathway is observed where Au(I) acts as a pi-Lewis base catalyst instead of a pi-Lewis acid to activate the allene, enabling the unusual addition of a carbon nucleophile. Density functional theory calculations were conducted to analyze this unconventional pathway.
Article
Chemistry, Multidisciplinary
Carlos Lazaro-Milla, M. Teresa Quiros, Diego J. Cardenas, Pedro Almendros
Summary: The synthesis of skipped 1,4-enynes through functionalization of the cyclobutene core with alkynes has been achieved, indicating an unusual pathway of oxidative addition in tertiary iodoalkanes.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
M. Teresa Quiros, Daniel Collado-Sanz, Elena Bunuel, Diego J. Cardenas
Summary: The formation of catalytically active alkyl-Ni(i) complexes through alkyl ligand exchange proceeds easily through triplet states, involving inversion of the configuration at the transferred carbon.
CHEMICAL COMMUNICATIONS
(2021)
