19391-29-8Relevant articles and documents
Ag2O nanoparticle-catalyzed substrate-controlled regioselectivities: direct access to 3-ylidenephthalides and isocoumarins
Chaudhary, Sandeep,Shyamlal, Bharti Rajesh K.,Yadav, Lalit,Tiwari, Mohit K.,Kumar, Krishan
, p. 23152 - 23162 (2018/07/10)
Herein, we disclose the first example of an efficient, silver oxide nanoparticle-catalyzed, direct regioselective synthesis of 3-ylidenephthalides 11-16 and isocoumarins 17-20via sonogashira type coupling followed by substrate-controlled 5-exo-dig or 6-endo-dig cyclization reaction, respectively. This one pot coupling involves reaction of substituted 2-halobenzoic acid with meta/para-substituted and ortho-substituted terminal alkynes, which proceeded in a regioselective manner resulting in the formation of 3-ylidenephthalides or isocoumarins, respectively, in excellent yields (up to 95%) with complete Z-selectivity. This protocol features relatively broad substrate scope, mild conditions, operational simplicity, and is favourable with aromatic/alicyclic terminal alkynes. The competition experiments and gram-scale synthesis further highlight the importance and versatility of the methodology. The proposed mechanistic pathways illustrate that the regioselectivity is substantially being controlled by the substituent(s) present on the acetylenic phenyl ring.
One-pot synthesis of phthalides via regioselective intramolecular cyclization from ortho-alkynylbenzaldehydes
Li, Jim,Chin, Elbert,Lui, Alfred S.,Chen, Lijing
scheme or table, p. 5937 - 5939 (2010/11/21)
A one-pot synthesis of phthalides via an intramolecular 5-exo-dig cyclization of ortho-alkynylbenzaldehydes under mild NaClO2 oxidation conditions is described.
Atropisomerism in o-Arylacetyl-N,N-dimethylbenzamides
Jones, Paul R.,Weisman, Gary R.,Baillargeon, Maurice J.,Gosink, Thomas A.
, p. 3618 - 3620 (2007/10/02)
A series of o-arylacetyl-N,N-dimethylbenzamides, 1-7, being studied as models for chain tautomers, differed markedly in their 1H NMR spectral properties, as a function of the substituents R1-R4.In the two cases where substituents were placed ortho to the amide group, the benzylic protons were anisochronous at ambient temperatures.Reported dynamic 1H NMR results are consistent with concomitant C-N and aryl-CO torsional processes.The 13C carbonyl shifts are compared with those of model compounds.
