Reference

Ether Complexes of Tungsten with Two Different Binding Modes: An O-Bound Ether and an h2-(C:C) Vinyl Ether

Ether Complexes of Tungsten with Two Different Binding Modes: An O-Bound Ether and an h2-(C:C) Vinyl Ether. Evidence for C-H×××O Hydrogen Bonding of Vinylic C-H Groups. Song, Jeong-Sup; Szalda, David J.; Bullock, R. Morris (Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA). Journal of the American Chemical Society, 118(45), 11134-11141 (English) 1996 American Chemical Society. CODEN: JACSAT. ISSN: 0002-7863. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 75 The reaction of PhCH(OCH3)2 with Cp(CO)3WH and HOTf gives [Cp(CO)3W(PhCH2OCH3)]+OTf-. The structure of this benzyl Me ether complex was detd. by single crystal x-ray diffraction and was shown to have the ether bonded to tungsten through the oxygen.Several reagents with their cas registry numbers 6044-68-4 and 184370-75-0 are used here. This compd. was isolated as a kinetic product of the reaction; it decomps. in soln. by releasing free PhCH2OCH3 and forming Cp(CO)3WOTf. An analog with the BAr'4- counterion [Ar' = 3,5-bis(trifluoromethyl)phenyl] is more stable. The reaction of the vinyl acetal CH2:CHCH(OEt)2 with Cp(CO)3WH and HOTf produces [Cp(CO)3W(h2-EtOCH:CHCH3)]+OTf-, in which the ether is bonded to tungsten through the C:C bond of the vinyl ether. The crystal structure of this compd. shows that the W-C(OEt) distance (2.69(3) ?) is significantly longer than the W-C(CH3) distance (2.37(3) ?). There are weak C-H×××O hydrogen bonds between both vinyl CH's and oxygens of triflate counterions. Evidence is presented that some of these weak hydrogen bonds are maintained in CD2Cl2 soln. but not in CD3CN. .

2-Amino-4-(hydroxyphosphinyl)butyric acid

2-Amino-4-(hydroxyphosphinyl)butyric acid. (Meiji Seika Kaisha, Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 58219191 A2 20 Dec 1983 Showa, 6 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C07F009-30. APPLICATION: JP 82-100614 14 Jun 1982.Some commonly used reagents like 89131-42-0 and 6044-68-4 are used in this experiment. DOCUMENT TYPE: Patent CA Section: 34 (Amino Acids, Peptides, and Proteins) Section cross-reference(s): 29 HP(O)(OH)CH2CH2CH(NH2)CO2H (I) was prepd. by, e.g., reaction of H2P(O)OM (II; M = alkali metal) with H2C:CHCH(OR)2 [III; R = alkyl, aryl, (substituted) phenyl], deacetalation of HP(O)(OR1)CH2CH2CH(OR)2 (IV; R1 = H, M), reaction of HP(O)(OH)CH2CH2CHO (V) with M1CN (M1 = Na, K), NH4Cl, and aq. NH3, and hydrolysis of HP(O)(OH)CH2CH2CH(NH2)CN. Thus, a mixt. of 5.3 g II.H2O (M = Na), 5.1 g III (R = Me), and 150 mL 2,2-bis(tert-butylperoxy)butane in MeOH was autoclaved 2 h at 120° to give 5.8 g IV (R = Me, R1 = Na), treatment of which (5 g) with hydroquinone and 36% HCl in aq. Me2CO 1.5 h at 50° and then with NaHCO3 gave 5.7 g V Na salt, autoclaving of which (4.6 g) with 24 mL 28% aq. NH3, 1.4 g NH4Cl, and 1.48 g KCN 3 h at 130° and heating the product with 40 mL 6 N HCl 6 h at 120° gave 1.8 g DL-I.HCl. .