Article
Chemistry, Organic
Khyarul Alam, Tian Li, I. F. Dempsey Hyatt, Mitchell P. Croatt
Summary: This study reports the regioselective intermolecular mono- or bis-hydroalkoxylation reactions of allenamides with alcohols under simple aluminum-catalyzed reaction conditions. Depending on the reaction conditions, the products can be N,O-acetals, gamma-substituted ethers, or 1,3-bis(alkoxy)propanamines. These reactions exhibit good functional group tolerance and efficiency.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Antonia Becker, Christian P. Grugel, Bernhard Breit
Summary: In this study, a new synthetic method is reported for the efficient preparation of biologically active compounds.
Article
Chemistry, Multidisciplinary
Hannah S. Slocumb, Shaozhen Nie, Vy M. Dong, Xiao-Hui Yang
Summary: This study demonstrates the first enantioselective hydroselenation of styrenes, accessing organoselenium building blocks with selectivity for the branched isomer. Through a Rh-hydride pathway, C-Se bonds can be formed with excellent regio- and enantiocontrol.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
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, Organic
Guangyang Xu, Zhen Wang, Ying Shao, Jiangtao Sun
Summary: An enantioselective copper-catalyzed tandem cross-coupling/alkynylogous aldol reaction has been developed, yielding tetrasubstituted allenoates with central and axial chirality. This protocol utilizes copper(II) salts as a catalytic precursor, distinguishing it from previous methods using Cu(I) salts.
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
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, Organic
Wei-Dong Lu, Yu Zheng, Zhi-Peng Zhang, Hong-Bin Chen, Kai Chen, Hao-Yue Xiang, Hua Yang
Summary: In this study, a visible-light-induced palladium-catalyzed desaturation/sulfonation cascade is reported, providing a concise method for the synthesis of highly valuable 4-sulfonyltetrahydropyridine scaffolds from inexpensive and readily available piperidine derivatives with sodium sulfinates. The success of this transformation relies on the well-designed sequence of palladium-mediated 1,5-hydrogen atom transfer/β-hydride elimination/allylic sulfonation process, highlighting the potential of orchestrating synthetic events through rational utilization of varied catalytic modes.
Article
Chemistry, Multidisciplinary
Kosuke Ito, Tsuyoshi Taniguchi, Tatsuya Nishimura, Katsuhiro Maeda
Summary: A substantially improved method for living polymerization of N-propargylamides and their derivatives has been developed using rhodium(I) complexes as initiators. The method enables the synthesis of cis-stereoregular polymers with a narrow molecular weight distribution and allows functionalization of polymer chain ends and synthesis of block copolymers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Dino Berthold, Bernhard Breit
Summary: A concise synthesis of (R)-sitagliptin monophosphate, a drug used for treating type 2 diabetes, was reported. A new approach for the construction of the inherent chiral amino function was established on a 3.5 mmol scale using the Rh-I-catalyzed hydroamination of allenes.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
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.
