58203-68-2Relevant academic research and scientific papers
Enantio- and Regioselective Palladium(II)-Catalyzed Dioxygenation of (Aza-)Alkenols
Giofrè, Sabrina,Molteni, Letizia,Nava, Donatella,Lo Presti, Leonardo,Beccalli, Egle Maria
supporting information, p. 21723 - 21727 (2021/09/08)
An oxidative Pd-catalyzed intra-intermolecular dioxygenation of (aza-)alkenols has been reported, with total regioselectivity. To study the stereoselectivity, different chiral ligands as well as different hypervalent-iodine compounds have been compared. I
Asymmetric "clip-Cycle" Synthesis of Pyrrolidines and Spiropyrrolidines
Maddocks, Christopher J.,Ermanis, Kristaps,Clarke, Paul A.
supporting information, p. 8116 - 8121 (2020/11/02)
The development of an asymmetric "clip-cycle"synthesis of 2,2- and 3,3-disubstituted pyrrolidines and spiropyrrolidines, which are increasingly important scaffolds in drug discovery programs, is reported. Cbz-protected bis-homoallylic amines were activate
Synthesis of Bicyclo[n.1.0]alkanes by a Cobalt-Catalyzed Multiple C(sp3)?H Activation Strategy
Zhang, Zhuo-Zhuo,Han, Ye-Qiang,Zhan, Bei-Bei,Wang, Sai,Shi, Bing-Feng
supporting information, p. 13145 - 13149 (2017/09/28)
A cobalt-catalyzed dual C(sp3)?H activation strategy has been developed and it provides a novel strategy for the synthesis of bicyclo[4.1.0]heptanes and bicyclo[3.1.0]hexanes. A key to the success of this reaction is the conformation-induced methylene C(sp3)?H activation of the resulting cobaltabicyclo[4.n.1] intermediate. In addition, the synthesis of bicyclo[3.1.0]hexane from pivalamide, by a triple C(sp3)?H activation, has also been demonstrated.
Towards stapling of helical alleno-acetylene oligomers - Synthesis of an enantiopure bis(ethynylvinylidene)-substituted cyclohexadeca-1,3,9,11-tetrayne
Mueller, I.-E. Sophie,Bernet, Bruno,Dengiz, Cagatay,Schweizer, W. Bernd,Diederich, Francois
supporting information, p. 941 - 953 (2014/03/21)
We are interested in developing strategies to bridge ("staple") enantiomerically pure acyclic alleno-acetylenic oligomers to enhance their conformational preferences for helical secondary structures, which are postulated to be at the origin of their exceptional chiroptical properties. We found that ring-closing metathesis (RCM), which has been used for the stapling of peptide helices, failed with an acyclic alleno-acetylene dimer decorated with lateral olefinic side chains. Instead, enyne RCM to an enantiomerically pure dienyne occurred. We switched to the introduction of diacetylene-containing bridges and report here the 15-step synthesis of a moderately strained, enantiomerically pure cyclohexa-1,3,9,11-tetrayne with an oxidative acetylenic coupling in the key step. The chiroptical properties of the new compounds are discussed. To stabilize the secondary helical structures and enhance the chiroptical properties of alleno-acetylenic oligomers by covalent linkage, two cyclization methods of enantiopure dimers (ring-closing metathesis and Hay coupling) were investigated. Olefin metathesis failed owing to concurrent enyne metathesis. Hay coupling afforded an enantiopure 16-membered macrocycle in 15 steps. Copyright
Towards Stapling of Helical Alleno-Acetylene Oligomers - Synthesis of an Enantiopure Bis(ethynylvinylidene)-Substituted Cyclohexadeca-1,3,9,11-tetrayne
Müller, I.-E. Sophie,Bernet, Bruno,Dengiz, Cagatay,Schweizer, W. Bernd,Diederich, Fran?ois
supporting information, p. 941 - 953 (2015/10/05)
We are interested in developing strategies to bridge ("staple") enantiomerically pure acyclic alleno-acetylenic oligomers to enhance their conformational preferences for helical secondary structures, which are postulated to be at the origin of their exceptional chiroptical properties. We found that ring-closing metathesis (RCM), which has been used for the stapling of peptide helices, failed with an acyclic alleno-acetylene dimer decorated with lateral olefinic side chains. Instead, enyne RCM to an enantiomerically pure dienyne occurred. We switched to the introduction of diacetylene-containing bridges and report here the 15-step synthesis of a moderately strained, enantiomerically pure cyclohexa-1,3,9,11-tetrayne with an oxidative acetylenic coupling in the key step. The chiroptical properties of the new compounds are discussed. To stabilize the secondary helical structures and enhance the chiroptical properties of alleno-acetylenic oligomers by covalent linkage, two cyclization methods of enantiopure dimers (ring-closing metathesis and Hay coupling) were investigated. Olefin metathesis failed owing to concurrent enyne metathesis. Hay coupling afforded an enantiopure 16-membered macrocycle in 15 steps.
Platinum-catalyzed intramolecular hydrohydrazination: Evidence for alkene insertion into a Pt-n bond
Hoover, Jessica M.,Dipasquale, Antonio,Mayer, James M.,Michael, Forrest E.
body text, p. 5043 - 5053 (2010/06/13)
Dicationic (bpy)Pt(II) complexes were found to catalyze the intramolecular hydrohydrazination of alkenes. Reaction optimization revealed Pt(bpy)Cl 2 (10 mol %) and AgOTf (20 mol %) in DMF-d7 to be an effective catalyst system for the conversion of substituted hydrazides to five- and six-membered N-amino lactams (N-amino = N-acetamido at 120 A°C, N-phthalimido at 80 A°C, -OTf = trifluoromethanesulfonate). Of the four possible regioisomeric products, only the product of 5-exo cyclization at the proximal nitrogen is formed, without reaction at the distal nitrogen or 6-endo cyclization. The resting states were found to be a 2:1 Pt-amidate complex (25, for N-acetamido) of the deprotonated hydrazide and a Pt-alkyl complex of the cyclized pyrrolidinone (20 for N-phthalimido). Both complexes are catalytically competent. Catalysis using 25 as the precatalyst shows no rate dependence on added acid (HOTf) or base (2,6-lutidine). The available mechanistic data are all consistent with a mechanism involving N-H activation of the hydrazide, followed by insertion of the alkene into the Pt-N bond, and finally protonation of the resulting cyclized alkyl complex by hydrazide to release the hydrohydrazination product and regenerate the active Pt-amidate catalyst.
Intramolecular additions of alcohols and carboxylic acids to inert olefins catalyzed by silver(I) triflate
Yang, Cai-Guang,Reich, Nicholas W.,Shi, Zhangjie,He, Chuan
, p. 4553 - 4556 (2007/10/03)
(Chemical Equation Presented) Intramolecular additions of hydroxyl or carboxyl groups to inert olefins catalyzed by simple silver(I) triflate are described. Good to excellent yields can be obtained for a range of substrates under relatively mild conditions. This reaction represents one of the simplest methods to construct cyclic ethers or lactones.
Palladium-catalyzed intramolecular oxidative alkylation of 4-pentenyl β-dicarbonyl compounds
Liu, Cong,Wang, Xiang,Pei, Tao,Widenhoefer, Ross A.
, p. 6343 - 6352 (2007/10/03)
Reaction of 8-nonene-2,4-dione with a catalytic amount of [PdCl 2(CH3CN)2] (2; 5 mol%) and a stoichiometric amount of CuCl2 (2.5 equiv) at room temperature for 3 h led to oxidative alkylation and formation of 2-
Palladium-catalyzed intramolecular oxidative alkylation of unactivated olefins
Pei, Tao,Wang, Xiang,Widenhoefer, Ross A.
, p. 648 - 649 (2007/10/03)
Reaction of 5,5-dimethyl-8-nonene-2,4-dione catalyzed by PdCl2(CH3CN)2 (5 mol %) in the presence of CuCl2 (2.5 equiv) at room temperature for 3 h formed 2-acetyl-3,6,6-trimethyl-2-cyclohexenone in 96% isolated yield. Palladium-catalyzed intramolecular oxidative alkylation tolerated a range of substitution and was applicable to the synthesis of spirobicyclic compounds and to the cyclization of ζ-alkenyl β-keto esters. Copyright
Reactions of β-trimethylstannylcyclohexanones with peracids: Investigations into the stannyl-directed Baeyer-Villiger reaction
Horvat, Sonia,Karallas, Panagoitis,White, Jonathan M.
, p. 2151 - 2154 (2007/10/03)
The trimethylstannyl subsituent raises the migratory aptitude of a primary β-carbon to be above that of a not otherwise activated secondary or tertiary carbon. This is apparent from the exclusive formation of the alkene acids 9-11 from Baeyer-Villiger reaction of the β-stannyl cyclohexanones 3-5. The stereoelectronic requirements of the stannyl-directed Baeyer-Villiger reaction were investigated using the axial β-trimethylstannlcyclohexanone 20.
