- Structure of 4-(2-chloro-4,5-dimethoxybenzylidene)-2-methyl-5-oxazolone. X-ray and NMR study
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The azlactone of 6-chloroveratraldehyde 3 (4-(2-chloro-4,5-dimethoxybenzylidene)-2-methyl-5-oxazolone) was synthesized from 6-chloroveratraldehyde 2 and its structure investigated using X-ray crystallographic and nuclear magnetic resonance methods. Compound 3 crystallized in the P21/c (#14) space group (Z = 4) with cell dimensions a = 9.148(2), b = 22.938(2), c = 6.707(1) A, and β = 111.50(2)°. The X-ray study shows that azlactone 3 exists as the Z-isomer and crystallizes as a planar structure, i.e., both the phenyl and azlactone ring systems, as well as the functional groups attached to them, lie in the same plane. The 1H and 13C NMR spectral values also support the formation of the Z-isomer only, during the synthesis of 4-(2-chloro-4,5-dimethoxybenzylidene)-2-methyl-5-oxazolone.
- Haasbroek,Oliver,Carpy
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- Monodentate Transient Directing Group Enabled Pd-Catalyzed Ortho-C-H Methoxylation and Chlorination of Benzaldehydes
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We report Pd-catalyzed ortho-C-H methoxylation and chlorination of benzaldehydes by employing monodentate transient directing groups (TDGs) as an alternative strategy to bidentate TDGs. More importantly, a single crystal of benzaldehyde imine ortho-cyclopalladium intermediate was successfully obtained, and its structure was unambiguously determined by X-ray diffraction, which clearly showed that it was a binuclear palladium species bridged by a pyridone ligand. The utility of this approach was further demonstrated through the synthesis of key intermediates of natural products and drugs.
- Li, Feng,Zhou, Yirong,Yang, Heng,Wang, Ziqi,Yu, Qinqin,Zhang, Fang-Lin
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supporting information
p. 3692 - 3695
(2019/05/24)
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- Diverse ortho-C(sp2)-H functionalization of benzaldehydes using transient directing groups
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Pd-catalyzed C-H functionalizations promoted by transient directing groups remain largely limited to C-H arylation only. Herein, we report a diverse set of ortho-C(sp2)-H functionalizations of benzaldehyde substrates using the transient directing group strategy. Without installing any auxiliary directing group, Pd(II)-catalyzed C-H arylation, chlorination, bromination, and Ir(III)-catalyzed amidation, could be achieved on benzaldehyde substrates. The transient directing groups formed in situ via imine linkage can override other coordinating functional groups capable of directing C-H activation or catalyst poisoning, significantly expanding the scope for metal-catalyzed C-H functionalization of benzaldehydes. The utility of this approach is demonstrated through multiple applications, including late-stage diversification of a drug analogue.
- Liu, Xi-Hai,Park, Hojoon,Hu, Jun-Hao,Hu, Yan,Zhang, Qun-Liang,Wang, Bao-Long,Sun, Bing,Yeung, Kap-Sun,Zhang, Fang-Lin,Yu, Jin-Quan
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supporting information
p. 888 - 896
(2017/05/16)
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- A straightforward and versatile protocol for the direct conversion of benzylic azides to ketones and aldehydes
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The synthesis of carbonyl compounds from benzylic azides through benzylideneamides is described for the first time. NaH-mediated activation of benzyl azides allows a rapid water-promoted oxidation under a facile protocol with good yields.
- González-Calderón, Davir,Morales-Reza, Marco A.,Díaz-Torres, Eduardo,Fuentes-Benítes, Aydeé,González-Romero, Carlos
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p. 83547 - 83550
(2016/10/12)
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- PYRAZOLO-HETEROARYL COMPOUNDS USEFUL TO TREAT TNF-ALPHA AND IL-1 MEDIATED DISEASES
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A compound of formula (I) wherein the groups R1-R4, X and Y are as defined in the specification, useful to treat TNF-Alpha and IL-1 mediated diseases.
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Page/Page column 16-17
(2008/06/13)
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- Comparative α- and β-adrenoceptor activity of 2- and 6-ring-chlorinated noradrenaline analogues
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The α- and β-adrenoceptor activity of the 2- and 6-ring-chlorinated analogues of noradrenaline (norepinephrine) were evaluated in vitro. The 2-chloro-substituted analogue exhibits a far greater affinity for β1-chronotropic receptors than the 6-chloro-substituted analogue, whereas no significant differences are apparent for their α-adrenergic affinities.
- Squier,Van der Schyf,Oliver,Venter
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p. 457 - 460
(2007/10/02)
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