198889-20-2Relevant academic research and scientific papers
Controlling Enantioselectivity and Diastereoselectivity in Radical Cascade Cyclization for Construction of Bicyclic Structures
Lee, Wan-Chen Cindy,Mckillop, Alexander M.,Wang, Duo-Sheng,Zhang, Congzhe,Zhang, X. Peter
supporting information, p. 11130 - 11140 (2021/07/31)
Radical cascade cyclization reactions are highly attractive synthetic tools for the construction of polycyclic molecules in organic synthesis. While it has been successfully implemented in diastereoselective synthesis of natural products and other complex compounds, radical cascade cyclization faces a major challenge of controlling enantioselectivity. As the first application of metalloradical catalysis (MRC) for controlling enantioselectivity as well as diastereoselectivity in radical cascade cyclization, we herein report the development of a Co(II)-based catalytic system for asymmetric radical bicyclization of 1,6-enynes with diazo compounds. Through the fine-tuning of D2-symmetric chiral amidoporphyrins as the supporting ligands, the Co(II)-catalyzed radical cascade process, which proceeds in a single operation under mild conditions, enables asymmetric construction of multisubstituted cyclopropane-fused tetrahydrofurans bearing three contiguous stereogenic centers, including two all-carbon quaternary centers, in high yields with excellent stereoselectivities. Combined computational and experimental studies have shed light on the underlying stepwise radical mechanism for this new Co(II)-based cascade bicyclization that involves the relay of several Co-supported C-centered radical intermediates, including α-, β-, γ-, and ?-metalloalkyl radicals. The resulting enantioenriched cyclopropane-fused tetrahydrofurans that contain a trisubstituted vinyl group at the bridgehead, as showcased in several stereospecific transformations, may serve as useful intermediates for stereoselective organic synthesis. The successful demonstration of this new asymmetric radical process via Co(II)-MRC points out a potentially general approach for controlling enantioselectivity as well as diastereoselectivity in synthetically attractive radical cascade reactions.
Efficient Pd-Catalyzed Regio- and Stereoselective Carboxylation of Allylic Alcohols with Formic Acid
Fu, Ming-Chen,Shang, Rui,Cheng, Wan-Min,Fu, Yao
supporting information, p. 8818 - 8822 (2017/07/11)
Formic acid is efficiently used as a C1 source to directly carboxylate allylic alcohols in the presence of a low loading of palladium catalyst and acetic anhydride as additive to afford β,γ-unsaturated carboxylic acids with excellent chemo-, regio-, and stereoselectivity. The reaction proceeds through a carbonylation process with in situ-generated carbon monoxide under mild conditions, avoiding the use of high-pressure gaseous CO. A bisphosphine ligand with a large bite angle (4,5-bis{diphenylphosphino}-9,9-dimethylxanthene, Xantphos) was found to be uniquely effective for this transformation. The regio- and stereoconvergence of this reaction is ascribed to the thermodynamically favored isomerization of the allylic electrophile in the presence of the palladium catalyst.
Novel compounds, their preparation and use
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Page/Page column 29; 30, (2010/02/11)
Novel compounds of the general formula (I), the use of these compounds as pharmaceutical compositions, pharmaceutical compositions comprising the compounds and methods of treatment employing these compounds and compositions. The present compounds may be u
NOVEL COMPOUNDS, THEIR PREPARATION AND USE
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Page 53, (2010/02/06)
Novel compounds of the general formula (I), the use of these compounds as pharma-ceutical compositions, pharmaceutical compositions comprising the compounds and methods of treatment employing these compounds and compositions. The present compounds may be
Synthesis of novel diazatricyclodecanes (DTDs). Effects of structural variation at the C3′ allyl end and at the phenyl ring of the cinnamyl chain on μ-receptor affinity and opioid antinociception
Pinna, Gerard Aime,Cignarella, Giorgio,Ruiu, Stefania,Loriga, Giovanni,Murineddu, Gabriele,Villa, Stefania,Grella, Giuseppe Enrico,Cossu, Gregorio,Fratta, Walter
, p. 4015 - 4026 (2007/10/03)
Two series of analogues of 9-propionyl-10-cinnamyl-9,10-diazatricyclo[4.2.1.12,5]decane (1a) and 2-propionyl-7-cinnamyl-2,7-diazatricyclo[4.4.0.03,8]decane (2a), in which the cinnamyl moiety was replaced by various aralkenyl chains,
N-3(9)-arylpropenyl-N-9(3)-propionyl-3,9-diazabicyclo[3.3.1]nonanes as μ-opioid receptor agonists. Effects on μ-affinity of arylalkenyl chain modifications
Pinna, Gérard A.,Cignarella, Giorgio,Loriga, Giovanni,Murineddu, Gabriele,Mussinu, Jean-Mario,Ruiu, Stefania,Fadda, Paola,Fratta, Walter
, p. 1929 - 1937 (2007/10/03)
Two series of N-3-arylpropenyl-N-9-propionyl-3,9-diazabicyclo[3.3.1]nonanes (1b-j) and of the reverted N-3-propionyl-N-9-arylpropenyl isomers (2b-j) as analogues of the previously reported analgesic N-3(9)-cinnamyl-N-9(3)-propionyl-3,9-diazabicyclo[3.3.1]nonanes (DBN) (1a, 2a) were synthesised and their affinity and selectivity towards opioid μ-, δ- and κ-receptors were evaluated. Several compounds (1e,i,j-2d,e,f,g,j) exhibited a μ-affinity in the low nanomolar range with moderate or negligible affinity towards δ- and κ-receptors. The representative term N-9-(3,3-diphenylprop-2-enyl)-N-3-propionyl-DBN (2d) displayed in vivo (mouse) a potent analgesic effect (ED50 3.88 mg/kg ip) which favourably compared with that of morphine (ED50 5 mg/kg ip). In addition, 2d produced in mice tolerance after a period twice as long with morphine.
