91962-89-9Relevant academic research and scientific papers
Synthesis of 5-Iodo-1,2,3,4-tetrahydropyridines by Rhodium-Catalyzed Tandem Nucleophilic Attacks Involving 1-Sulfonyl-1,2,3-triazoles and Iodides
Man, Zengming,Dai, Haican,Shi, Yinping,Yang, Dongdong,Li, Chuan-Ying
, p. 4962 - 4965 (2016)
Sodium iodide is used for the first time as a nucleophile to trap an α-imino rhodium carbene, which triggers a tandem process involving intermolecular nucleophilic attack and intramolecular SN2 reaction. A series of 5-iodo-1,2,3,4-tetrahydropyridines are obtained in high yield, and the synthetic utility of the products is demonstrated in cross-coupling reactions and the construction of biorelated polycyclic compounds.
Remote Cooperative Group Strategy Enables Ligands for Accelerative Asymmetric Gold Catalysis
Wang, Zhixun,Nicolini, Corrado,Hervieu, Cedric,Wong, Yuk-Fai,Zanoni, Giuseppe,Zhang, Liming
supporting information, p. 16064 - 16067 (2017/11/22)
An accelerative asymmetric gold catalysis is achieved for the first time via chiral ligand metal cooperation. An asymmetrically positioned remote amide group in the designed chiral binaphthyl-based ligand plays the essential role of a general base catalyst and selectively accelerates the cyclizations of 4-allen-1-ols into one prochiral allene face. The reactions are mostly highly enantioselective with achiral substrates, and due to the accelerated nature of the catalysis catalyst loadings as low as 100 ppm are allowed. With a pre-existing chiral center at any of the backbone sp3-carbons, the reaction remained highly efficient and most importantly maintained excellent allene facial selectivities regardless of the substrate stereochemistry. By using different combinations of ligand and substrate enantiomers, it is now possible to access all four stereoisomers of versatile 2-vinyltetrahydrofurans with exceedingly high selectivity. The underpinning design of this chemistry reveals a novel and conceptually distinctive strategy to tackle challenging asymmetric gold catalysis, which to date has relied on decelerative asymmetric steric hindrance approaches.
Highly regio- and stereoselective hydrostannylation of alkynols with a new Lewis acidic hydrostannane
Miura, Katsukiyo,Wang, Di,Matsumoto, Yukihiro,Hosomi, Akira
, p. 503 - 505 (2007/10/03)
(Chemical Equation Presented) Bu2Sn(OTf)H (1a), easily prepared from Bu2SnH2 and TfOH, was found to be very valuable for highly regio- and stereoselective hydrostannylation of various propargyl alcohols leading to (Z)-γ-st
Non-peptidyl inhibitors of VLA-4 dependent cell binding useful in treating inflammatory, autoimmune, and respiratory diseases
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, (2008/06/13)
There is disclosed a genus of non-peptidyl compounds, wherein said compounds are VLA-4 inhibitors useful in treating inflammatory, autoimmune, and respiratory diseases, and wherein said compounds comprise a compound of Formula (1.0.0): and pharmaceutically acceptable salts and other prodrug derivatives thereof, wherein: A is (C1-C6) alkyl, cycloalkyl, aryl, heteroaryl or heterocyclyl optionally substituted with 0 to 3 R9; or is a member selected from the group consisting of the following radicals: A1-NHC(═O)NH-A2-, A1-NHC(═O)O-A2-, A1-OC(═O)NH-A2-, A1-NHSO2NH-A2-, A1-NHC(═O)-A2-, A1-C(═O)NH-A2-, A1-NHSO2-A2-, A1-SO2NH-A2-, A1-(CH2)r-A2-, where A1 and A2 are each independently selected from the group consisting of hydrogen, aryl, (C1-C6) alkyl, (C2-C6) alkenyl, (C2-C6) alkynyl, cycloalkyl, heteroaryl, and heterocyclyl substituted with 0 to 3 R9; B is a member independently selected from the group consisting of the following: E is a single bond; —O—; —NR10—; —CH═CH—; —CC—; —S(═)q; —CR11R12NR10—; or —CR11R12; X is —O—; —C(═O)—; —S(═O)q—; or —NR10—; X1, X2 and X3 are each independently selected from the group consisting of CH, CR9 or N; Y is a single bond; —C(═O)—; —C(═S)—; or —S(═O)2—; R7 is (C1-C6) alkyl; (CH2)kOR5; (CH2)kNR6C(═O)R5; (CH2)kNR6C(═O)OR5; (CH2)kNR6SO2R5; (CH2)kNR6R5; F; CF3; OCF3; aryl, substituted with 0 to 3 R9; heterocyclyl, substituted with 0 to 3 R9; heteroaryl, substituted with 0 to 3 R9; cycloalkyl, substituted with 0 to 3 R9; or R7 may be taken together with R8 to form a cycloalkyl or heterocyclyl ring; or R7 may be taken together with R11 to form a cycloalkyl or heterocyclyl ring; and R8 is hydrogen; F; (C1-C6) alkyl or (C1-C6) alkoxy.
Acid-catalyzed cyclization of vinylsilanes bearing a hydroxy group: A new method for stereoselective synthesis of disubstituted tetrahydrofurans
Miura,Okajima,Hondo,Nakagawa,Takahashi,Hosomi
, p. 11348 - 11357 (2007/10/03)
In the presence of a catalytic amount of TsOH or TiCl4, (Z)-5-silyl-4-penten-1-ols ((Z)-1) are smoothly cyclized to 2-silylmethyl-substituted tetrahydrofurans. This cyclization is applicable to the construction of a tetrahydropyran ring. The silyl group and the geometry of the C-C double bond strongly influence the cychzation rate. TBDMS and benzyldimethylsilyl groups considerably accelerate the cyclization in comparison with a dimethylphenylsilyl group, and (E)-vinylsilanes show much lower reactivity than the corresponding (Z)-isomers. The cyclization proceeds by stereospecific syn addition of the hydroxy group. Vinylsilanes 17, 19, and 21, (Z)-5-silyl-4-penten-1-ols bearing a substituent on the methylene tether, smoothly undergo the acid-catalyzed cyclization to give trans-2,5-, cis-2,4-, and trans-2,3-disubstituted tetrahydrofurans, respectively, with moderate to high stereoselectivity. The silyl group of some cychzed products can be easily converted into a hydroxy group with stereochemical retention.
Design and Synthesis of Transition-state Analogues for a Cationic Cyclisation
Bell, Ian M.,Abell, Chris,Leeper, Finian J.
, p. 1997 - 2006 (2007/10/02)
Transition-state analogues based upon the 6-(hydroxymethyl)-13-azagona-1,3,5,(10),8-tetraene structure (e.g., 40) have been designed and synthesized as part of a programme to elicit antibodies capable of catalysing cationic cyclisations.Methodology for co
