130256-90-5Relevant articles and documents
Substituted 2,5-Dihydro-1,2,5-oxasilaboroles - Preparation, Complexations, and Ring-Opening
Koester, Roland,Seidel, Guenter,Boese, Roland,Wrackmeyer, Bernd
, p. 597 - 616 (2007/10/02)
The two 4,5-diethyl-2,5-dihydro-2,2-dimethyl-3-organo-1,2,5-oxasilaboroles are prepared from and water via the addition compounds in yields of about 90percent. 2a,b are also obtained directly from 1a,b with acetylacetone or with dry acetic acid. 1b can be prepared from sodium triethylhydroborate (A) via sodium triethyl(3-methyl-3-buten-1-ynyl)borate (B), (Z)-4-(diethylboryl)-2-methyl-3-(trimethylsilyl)-1,3-hexadiene (C), sodium aminodiethylborate (D), 4,5,5-triethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-sodio-1,2,5-azoniasilaboratole (E), and 4,5-diethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-sodio-1,2,5-azasilaborole (F).The behaviour of 2a,b towards trimethylphsophane (TMP), γ-picoline (formation of γ-Pic-2a), γ-picoline N-oxide (PNO-2a), trimethylamine N-oxide (2'a, 4, 4'a), methylenetriphenylphosphorane (MTPP-2a), aluminium trichloride (2a-AlCl3), triethylaluminium , trichloroborane (3a), dichloroethylborane (3b), phosphorus pentachloride (3a, 3b), methanol (6a), acetylacetone (5a), propanol (7a, 7c) and towards glacial acetic acid (7a, 9) is described. 5-Chloro-4-ethyl-2,5-dihydro-1,2,2,3-tetramethyl-1,2,5-azasilaborole (1c) is readily obainable from 1a and dichloroethylborane. η4-Complexations of 2b give 10b from (CH3CN)3Cr(CO)3, 11b and 11'b from Fe2(CO)9, 12b from Ru3(CO)12, 13b from C5H5Co(C2H4)2, and 14b from C5H5Rh(C2H4)2 (MS and NMR data).The O-exchange in several reactions was monitored by 17O NMR using 17O-enriched compounds (e.g. 2a*, triethylboroxin*, tetraethyldiboroxane*, water*, methanol*).