- Nickel-Catalyzed Intramolecular Hydroalkenylation of Imines
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A ligand-enabled nickel-catalyzed intramolecular hydroalkenylation of imines with unactivated alkenes has been developed. A variety of five- and six-membered cyclic allylic amines were synthesized in high yields. The use of both wide-bite-angle diphosphine ligand and Br?nsted acid is crucial for realizing the reaction. Preliminary investigation of the asymmetric intramolecular hydroalkenylation of imines shows promising potential for the application of the method in the synthesis of enantio-enriched cyclic allylic amines.
- Feng, Wei-Min,Li, Tian-Yu,Xiao, Li-Jun,Zhou, Qi-Lin
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supporting information
p. 7900 - 7904
(2021/10/12)
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- Visible-Light-Induced Tandem Radical Addition-Cyclization of Alkenyl Aldehydes Leading to Indanones and Related Compounds
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Herein we describe a novel, visible light-induced tandem radical addition-cyclization of alkenyl aldehydes with α-bromocarbonyl compounds. A set of cyclic ketones, including indanones, cyclopentenones, 3,4-dihydronaphthalen-1(2H)-ones, and chroman-4-ones,
- Lu, Danyang,Wan, Yimei,Kong, Lichun,Zhu, Gangguo
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supporting information
p. 2929 - 2932
(2017/06/07)
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- Synthesis of unsymmetrical heterobiaryls with winding vine-shaped molecular asymmetry through a condensation pathway
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Oxidative condensation of N-(3-buten-1-yl)-1,2-phenylenediamine with a formylated heteroarene bearing 3-buten-1-yl substituent gives unsymmetrical heterobiaryl in 42-86% yields. Ring-closing metathesis of the thus obtained product affords the cyclized product, which resulted in separation of each enantiomer by HPLC with a chiral column showing molecular asymmetry.
- Mori, Atsunori,Matsuoka, Daichi,Ashida, Shiomi,Inoue, Ryo,Maruhashi, Kazuki,Okayama, Yoichi,Jin, Guan Hong,Okano, Kentaro
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p. 268 - 276
(2017/07/28)
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- Application of Dehydroabietic Acid in Palladium-Catalysed Enyne Cycloisomerisation
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Dehydroabietic acid (DAA) promotes palladium(0)-catalysed cyclisations of arene-tethered 1,7-enynols and 1,m-enynoates (m=6,7) to give fused carbocyclic dienes. 6,6,6,5-Tetracyclic lactones are accessible by one-pot cycloisomerisation/Diels–Alder reaction
- Wu, Na,Li, Ruikun,Cui, Feihu,Pan, Yingming
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supporting information
p. 2442 - 2447
(2017/07/22)
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- Pyrazolopyrimidine Macrocycles as Inhibitors of Human Immunodeficiency Virus Replication
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The disclosure generally relates to compounds of formula I, including compositions and methods for treating human immunodeficiency virus (HIV) infection. The disclosure provides novel inhibitors of HIV, pharmaceutical compositions containing such compound
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Paragraph 0351; 0357
(2015/09/22)
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- Rhodium-catalyzed cycloisomerization involving cyclopropenes: Efficient stereoselective synthesis of medium-sized heterocyclic scaffolds
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A happy medium: The title reaction of cyclopropenyl carbinols and carbinylamines gives carbo- and heterocycles with a [6.1.0] bicyclic ring fused to an aromatic ring (see scheme, Alloc=allyloxycarbonyl, Boc=tert- butyloxycarbonyl). These reactions are the first examples of the formation of medium-sized rings by the intramolecular cyclopropanation of an alkene with a donor-substituted rhodium carbenoid, which is not generated from a diazo compound.
- Miege, Frederic,Meyer, Christophe,Cossy, Janine
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supporting information; experimental part
p. 5932 - 5937
(2011/08/02)
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- Cyanative alkene-aldehyde coupling: Ni(0)-NHC-Et2AlCN mediated chromanol synthesis with high cis-selectivity at room temperature
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Described are several classes of Ni(0) mediated cyanative alkene-aldehyde coupling reactions, providing 6-membered cores, which complement existing cyclization technology in several respects. Et2AlCN was used as both a cyclization accelerator and CN source. The NHC ligand may have a positive effect in differentiating reductive elimination and syn-β-hydride elimination.
- Ho, Chun-Yu
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supporting information; scheme or table
p. 466 - 468
(2010/05/01)
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- Efficient construction of oxa- and aza-[n.2.1] skeletons: Lewis acid catalyzed intramolecular [3+2] cycloaddition of cyclopropane 1,1-diesters with carbonyls and imines
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Chemical equation presented Building bridges: A Lewis acid promoted intramolecular [3+2] cycloaddition of cyclopropane 1,1-diesters with aldehydes, ketones, and imines (see scheme) has been developed to provide a general and efficient strategy for construction of bridged oxa- and aza-[n.2.1] (n = 2,3,4) skeletons. To highlight this method, the core of platensimycin was also constructed.
- Xing, Siyang,Pan, Wenyan,Liu, Chang,Ren, Jun,Wang, Zhongwen
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supporting information; experimental part
p. 3215 - 3218
(2010/07/10)
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- Palladium-catalyzed intramolecular carboesterification of olefins
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One catalyst three bonds: The title reaction between propiolic acids and unactivated olefins (see scheme; O red, Cl green) results in vicinal functionalization of the olefin, with the formation of new C-C and C-O bonds. Structurally complex 6,7,5-tricyclic ring systems are formed in a single step by this cascade chloropalladation and formal [3+2] cycloaddition.
- Li, Yang,Jardine, Katherine J.,Tan, Runyu,Song, Datong,Dong, Vy M.
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supporting information; experimental part
p. 9690 - 9692
(2010/04/28)
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- Acetylenic vinyllithiums: Consecutive cycloisomerization-[4 + 2] cycloaddition reactions
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Acetylenic vinyllithiums (2), which were generated from the corresponding acetylenic vinyl bromides (3) by low-temperature lithium-bromine exchange, cyclize on warming to give, following quench with water, isomerically pure conjugated bis-exocyclic 1,3-dienes (1) in good to excellent yield. Both five-membered and six-membered outer-ring dienes may be prepared: 5-exo closure of an acetylenic vinyllithium, which proceeds with total stereocontrol via syn-addition to give the E-isomer of a five-membered outer-ring diene, tolerates aryl-, silyl-, or alkyl-substituents at the distal acetylenic carbon; the corresponding 6-exo process is less facile and seems to be confined to substrates bearing an anion-stabilizing substituent, such as phenyl or trimethylsilyl, at the terminal acetylenic carbon. The highly reactive bis-exocyclic 1,3-dienes serve as precursors to polycyclic materials through subsequent Diels-Alder reaction with a wide variety of dienophiles. The consecutive exchange-cyclization-cycloaddition methodology, which can be conducted in one pot without isolation of intermediates, provides an efficient, operationally simple, and diastereoselective route to diverse polycyclic ring systems.
- Bailey, William F.,Wachter-Jurcsak, Nanette M.,Pineau, Mark R.,Ovaska, Timo V.,Warren, Rachel R.,Lewis, Carl E.
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p. 8216 - 8228
(2007/10/03)
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- Directed Metalation of Aromatic Aldimines with Lithium 2,2,6,6-Tetramethylpiperidide
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N-Cyclohexyl aromatic aldimines are ortho-lithiated or o-methyl-lithiated with 2 equiv of lithium 2,2,6,6-tetramethylpiperidide (LTMP) in THF solution at -15 deg C.The lithiated intermediates generally reacted with alkyl halides or CO2 to provide ortho-functionalized aldimine products which could be readily converted to the corresponding aldehydes by hydrolysis with aqueous 4 M HCl.Aromatic aldimines derived from (+/-)-trans-2-methylcyclohexylamine or 3-amino-2,4-dimethylpentane are resistant toward C=N addition with 1 equiv of n-BuLi at 0 deg C in THF solution; however, they are also surprisingly resistant toward directed metalation reactions with either LTMP or n-BuLi.Exceptions to the ortho-directing and o-methyl-directing effects of the aldimine group were observed in a reaction of 3-methylthiophene-2-carboxaldehyde cyclohexylimine (7) with LTMP, followed by CH3I, which gave a 9:1 mixture of 3,5-dimethylthiophene-2-carboxaldehyde cyclohexylimine (22) and 5-ethyl-3-methylthiophene-2-carboxaldehyde cyclohexylimine (23), and a reaction of p-tolualdehyde 2,4-dimethylpent-3-ylimine (11) with either n-BuLi or LTMP, followed by CH3I, which gave p-ethylbenzaldehyde 2,4-dimethylpent-3-ylimine (25).
- Flippin, Lee A.,Muchowski, Joseph M.,Carter, David S.
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p. 2463 - 2467
(2007/10/02)
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- Synthesis of polycyclic lactams via intramolecular dipolar cycloadditions of stabilized azomethine ylides
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A stereoselective two step sequence for the construction of fused pyrrolidone ring systems has been developed which features the intramolecular [3 + 2] dipolar cycloaddition of unsaturated azomethine ylides. The ylides are produced upon reaction of aminomethylphosphonates with α,ω-olefinic aldehydes, followed by oxidative removal of the phosphonate ester group using a newly developed method.
- Martin,Cheavens
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p. 7017 - 7020
(2007/10/02)
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- ACID CATALYZED INTRAMOLECULAR 2-AZA-1,3-DIENE DIELS-ALDER CYCLIZATION PROCESSES
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Preparation and acid-catalyzed Diels-Alder cyclizations of a 1-alkenyl-2-aza-1,3-diene have been explored.
- Ho, Eugene,Cheng, Yea-Shun,Mariano, Patrick S.
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p. 4799 - 4802
(2007/10/02)
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