14724-91-5Relevant academic research and scientific papers
Samarium(II) Diiodide Mediated Coupling of Bis(bromomethyl)arenes. Facile Synthesis of n>Cyclophanes without using High-Dilution Techniques
Takahashi, Senji,Mori, Nobuo
, p. 2029 - 2032 (2007/10/02)
In the presence of samarium(II) diiodide (Sml2), coupling of 1,3- and 1,4-bis(bromomethyl)benzenes proceeds smoothly to give their cyclic and acyclic oligomers.Use of 1.2 equiv. of Sml2 gives 1,2-bis(3- and 4-bromomethylphenyl)ethanes, respectively, in 95percent yield, and the use of 5.0 equiv. of Sml2 affords n>metacyclophanes and n>paracyclpphanes (n = 2, 3 and 4), respectively, in satisfactory yields.By using 5.0 equiv. of Sml2, 2-bromo- and 2-methoxy-1,4-bis(bromomethyl)benzenes and 1,4- and 2,6-bis(bromomethyl)naphthalenes each give only one of several expected isomeric cyclophanes as the major cyclic oligomer.
New Synthetic Method of Cyclophanes via Diselenacyclophanes
Higuchi, Hiroyuki,Tani, Keita,Otsubo, Tetsuo,Sakata, Yoshiteru,Misumi, Soichi
, p. 4027 - 4036 (2007/10/02)
Syntheses of cyclic diselenides through diselenolates and the following deselenation reactions by means of three ways were studied.The preparation of the cyclic diselenides in the presence of excess sodium borohydride gave thirty-eight diselenides containing diselenacyclophanes and alicyclic diseleno compounds in high yields in addition to two triple-bridged selenacyclophanes.Photodeselenation of the diselenides in tris(dimethylamino)phosphine afforded series of cyclophanes in much higher yields than those of the other two methods, i.e. benzyne-Stevens rearrangement/Raney nickel hydrogenolysis and pyrolytic deselenation at ca. 650 deg C.The present study demonstrates that the photodeselenation method combined with the synthesis of their precursor diselenides, is much superior to the conventional dechalcogenation methods.
