Reference

Metal-catalyzed oligomerization reactions of organosiloxanes

Metal-catalyzed oligomerization reactions of organosiloxanes. Curtis, M. David (Dep. Chem., Univ. Michigan, Ann Arbor, MI 48109, USA). J. Polym. Sci., Polym. Symp., 70(Polym. Unusual Prop.), 107-19 (English) 1983. CODEN: JPYCAQ. ISSN: 0360-8905. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) The use of transition metal complexes such as (Ph3P)2PtC2H4 [12120-15-9], (Ph3P)2RhCl [14694-95-2], and (Ph3P)2Ir(CO)Cl [15318-31-7] in the oligomerization of tetraalkyldisiloxanes to produce metallacycles featuring the transition metal (M), 2 Si, and O in a 4-membered ring (MSiOSi) was investigated. Stereoselectivity in the formation of the metallacycle from a mixt.There are some commonly used reagents with their cas registry numbers 12120-15-9 and 3277-26-7 in this article. of stereoisomers of (HMePhSi)2O was obsd. Selectivity for the desired exchange type (i.e. SiO groups for Si-H) increased when the catalysts were adsorbed on oxide supports. .

Selective catalytic hydrogenation of polynuclear heteroaromatic compounds using polymer-supported transition-metal compounds as catalyst

Selective catalytic hydrogenation of polynuclear heteroaromatic compounds using polymer-supported transition-metal compounds as catalyst. Fish, R. H.; Heinemann, H. (Lawrence Berkeley Lab., Berkeley, CA, USA). Report, LBL-19772; Order No. DE85016529, 38 pp. Avail. NTIS From: Energy Res. Abstr. 1985, 10(20), Abstr. No. 41129 (English) 1985. DOCUMENT TYPE: Report CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Section cross-reference(s): 67 This research program focused on the utilization of transition-metal catalysts supported on styrene-divinylbenzene copolymer [9003-70-7] in the hydrogenation of polycyclic heteroarom. compds. present in coal and coal liqs. The polymer-supported chlorotris(triphenylphosphine)rhodium (I) [14694-95-2] was the most efficient catalyst for the regiospecific redn. of the hetero ring in model coal compds. such as quinoline [91-22-5], and 5,6- [85-02-9], and 7,8-benzoquinoline [230-27-3], acridine [260-94-6], and benzothiophene [95-15-8]. The polymer-supported catalst was more active then the corresponding homogenous analog by relative rate factors of 10-20, depending on the substrate studied. A model coal liq. d. a relative rate of redn. of II 1,2,3,4-tetrahydroquinoline (III) [635-46-1] that was 2.2 times faster than a similar expt. 95-15-8 is also in the experiment. without the coal liq. constituents. The model coal liq. constituent p-cresol [106-44-5] was responsible for the relative rate enhancement in the highly regiospecific redn. of II to III. NMR expts. gave some insight into these rate-enhancement phenomena. 9,10-Dihydrophenanthridine [82692-08-8] was an excellent catalytic transfer hydrogenation reagent in the presence of several homogeneous and polymer-supported transition-metal catalysts. H was transferred to such acceptors as II. Also, dihydroquinoline [29968-14-7] was examd. as a donor solvent. .