163222-89-7Relevant articles and documents
Synthesis of benzocyclobutenes by palladium-catalyzed C-H activation of methyl groups: Method and mechanistic study
Chaumontet, Manon,Piccardi, Riccardo,Audic, Nicolas,Hitce, Julien,Peglion, Jean-Louis,Clot, Eric,Baudoin, Olivier
supporting information; experimental part, p. 15157 - 15166 (2009/03/12)
An efficient catalytic system has been developed for the synthesis of benzocyclobutenes by C-H activation of methyl groups. The optimal conditions employed a combination of Pd(OAc)2 and PtBu3 as catalyst, K2CO3 as the base, and DMF as solvent. A variety of substituted BCB were obtained under these conditions with yields in the 44-92% range, including molecules that are hardly accessible by other methods. The reaction was found limited to substrates bearing a quaternary benzylic carbon, but benzocyclobutenes bearing a tertiary benzylic carbon could be obtained indirectly from diesters by decarboxylation. Reaction substrates bearing a small substituent para to bromine gave an unexpected regioisomer that likely arose from a 1,4-palladium migration process. The formation of this "abnormal" regioisomer could be suppressed by introducing a larger subsituent para to bromine. DFT(B3PW91) calculations on the reaction of 2-bromo-tert-butylbenzene with Pd(PtBu3) with different bases (acetate, bicarbonate, carbonate) showed the critical influence of the coordination mode of the base to induce both an easy C-H activation and to allow for a pathway for 1,4-palladium migration. Carbonate is shown to be more efficient than the two other bases because it can abstract the proton easily and at the same time maintain κ1-coordination without extensive electronic reorganization.
Ramoplanin derivatives possessing antibacterial activity
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Page/Page column 38; 80, (2010/11/23)
Novel ramoplanin derivatives are disclosed. These ramoplanin derivatives exhibit antibacterial activity. As the compounds of the subject invention exhibit potent activities against gram positive bacteria, they are useful antimicrobial agents. Methods of synthesis and of use of the compounds are also disclosed.
A Novel Method for the Synthesis of Methyl Indane-1-carboxylates by Ring Contraction of Tetralones Using Lead(IV) Acetate
Nongrum, F.M.,Myrboh, B.
, p. 845 - 846 (2007/10/02)
A smooth ring contraction of the tetralones takes place with lead(IV) acetate in presence of boron trifluoride etherate and methanol to afford methyl indane-1-carboxylates in satisfactory yields.The method is extended to five- and seven-membered cyclic aromatic ketones.
FORMATION OF SUBSTITUTED BENZOCYCLOBUTENES THROUGH FLASH VACUUM PYROLYSIS
Schiess, Peter,Rutschmann, Suzanne,Toan, Van Vien
, p. 3669 - 3672 (2007/10/02)
Benzocyclobutenes carrying a substituent in the four membered ring are obtained in high yield from 2-methyl benzaldehydes through a reaction sequence involving a pyrolitic 1,4-elimination of HCl in the crucial step.
