2,5-Dimethyl-2,5-bis

The silacarborane analogue of C,C-dimethyl-o / o-carborane, closo-l]l-((C i]) -l]lSi[ fri [128270 8 ] h.3.s been reported (179). This o-sdacarborane, which has an icosahedral framework much like o-carborane and is reported to be stable to air and moisture, was obtained in low yield from the reaction of decaborane and bis (dimethyl amino)metbyl silane in refluxing benzene. 

The reduction of (aLkylarnino)haloboranes using hydride reagents can provide a convenient route to (aLkylamino)boranes for example, LiAlH has been utilized to prepare bis (dimethyl amino)borane [23884-11-9] from chi orobis (dimethyl amino)borane [6562-41-0] (68). When this same strategy is appHed to (bis(trimethylsi1y1)amino)ch1oro((trimethylsi1y1)amino)borane [10078-93-0] the expected compound is obtained along with the formation of two... 

The imonium salt (199), obtained from ynamines and phosgeneimonium chloVide, underwent ready reaction with monosubstituted hydrazines to give the 3,5-bis(dimethyl-amino)pyrazole (200) (68T4217, 69T3453). Similarly, the adduct (201), resulting from the addition of phosgene to ynamines, likewise reacted with sym-disubstituted hydrazines to give pyrazoles (202). With hydroxylamine derivatives the isoxazolinone (203) was obtained. 

In contrast to the 3-substituted products above, 4-chloro-, 4-bromo- and 4-iodo-isoxazoles are readily prepared by direct halogenation of the corresponding isoxazoles, from 4-isoxazolediazonium salts by the Sandmeyer reaction, or by reaction of hydroxylamine with a-halo- 8-dicarbonyl compounds (62HC(l7)l, p. 66, 63AHC(2)365). 3,5-Bis(dimethyl-amino)-4-fluoroisoxazole has been synthesized by reaction of (Me2NCO)2CHF with hydroxylamine (78BSB391). 

Ferrocene, reaction with bis(dimethyl-amino) methane to yield di-methylaminomethylferrocene, 40,31... 

Gegen den Angriff nucleophiler komplexcr Metallhydride konnen Lactone durch Obcrfuhrung mit 1,2-Bis-[dimethyl-aluminium-mercaptopathan in die ortho-Dithiosaure-triester geschiitzt werden" ... 

Benzenediamine (288) and the unstable oxamide equivalent (289), prepared in situ by chlorination of bis(dimethylamino)acetylene, gave 2,3-bis(dimethyl amino)quinoxaline (290) (no details). ... 

The Amine Complexes of Aluminium Hydride, IV. Bis-(dimethyl-aminoborane)-bis-(dimethylamino)-alane. Inorg. Chem. 1, 612 (1962). 

This agrees quite well with the rate constants for intramolecular proton transfer in 2,4-bis(dimethyl-amino )-6-(2-hydroxy-5-methylphenyl)-5-triazine which had been measured by Shizuka et al. ( l6) using laser picosecond spectroscopy. The fluorescence decay constant t of (TIN) was found to be 60 20 ps. Because of the weak intensity all fluorescence lifetimes refer to the pure substance in crystalline form at room temperature. 

Well-defined complicated macromolecular structures require complex synthetic procedures/techniques and characterization methods. Recently, several approaches leading to hyperbranched structures have been developed and will be the focus of this section. The preparation of hyperbranched poly(siloxysilane) has been reported [198] and is based on methylvinyl-bis(dimethyl siloxysilane), an A2B type monomer, and a progressive hydrosi-lylation reaction with platinum catalysts. An appropriate hydrosilylation reaction on the peripheral - SiH groups led to the introduction of polymeric chain (PIB, PEO) or functional groups (epoxy, - NH2) [199]. 

The only Zr(0) carbonyl complex has been prepared by Wreford and co-workers. When ZrCl4 was treated with l,2-bis(dimethyl-phosphino)ethane (dmpe), and then subsequently reduced with sodium amalgam in the presence of 1,3-butadiene, the dmpe bridged dimer, [(t/-C4H6)2Zr(dmpe)]2(dmpe) (65), resulted (114). The brown crystalline dimer 65 was found to be in equilibrium with the 16-e- coordinatively unsaturated complex, (tj-C4H6)2Zr(dmpe) (66), and free dmpe. When toluene solutions of 65 were exposed to CO at —45°C, 1 equivalent of CO per equivalent of Zr was consumed and the CO adduct (r/-C4H6)2Zr-(dmpe)(CO) (67) precipitated as a yellow solid. If these mixtures were allowed to warm above -22°C under vacuum, the precipitate dissolved and the consumed CO evolved (114). Complex 67 could be isolated by... 

The kinetics of proton transfer from protonated 1,8-bis(dimethyl-amino)-2,7-dimethoxynaphthalene to substituted phenolate ions (69) were studied in 70% (v/v) Me2SO—H20 using the temperature-jump technique with spectrophotometric detection to follow reactions with half-lives in the range 1-100 ms (Hibbert and Robbins, 1978). A limited... 

Alternatively (CA 72,66732(1970)), add 1.6 g 5-OH-indole, 1 g bis-dimethyl-aminomethane in 5 ml dioxane. Heat 2Vz hours on water bath to get 1 g (1) (recrystallize-methanol-dimethylfor-mamide). 

This synthetic strategy also proved to be also suitable for the ring closure to the related [l,3,4]triazolo[2,3-a][l,3,5]tri-azinium salts, as shown in Scheme 33 <1994JHC535, 1995JHC1833> reaction of 169 with l-chloro-l,3-bis(dimethyl-amino)-3-phenyl-2-azaprop-2-enylium perchlorate gave the quaternary salt 170 in 37% yield. 

An aqueous pATg-value of 16.1 has been measured for l,8-bis(dimethyl-amino)-2,7-dimethoxynaphthalene from studies in 35% (v/v) Me SO-HjO (Hibbert and Simpson, 1987a). The values of Ap/f, in Table 14 imply that [50], [51] and [52] are more acidic and [53] is less acidic than l,8-bis(dimethyl-amino)-2,7-dimethoxynaphthalene. Correspondingly, the amines derived from [50], [51] and [52] are less basic and that derived from [53] is more basic than l,8-bis(dimethylamino)-2,7-dimethoxynaphthalene. It follows that the amine 1,6-dimethyl-1,6-diazacyclodecane [53] is an extremely strong base in aqueous solution,... 

In (—)-sparteine-mediated deprotonation and electrophilic substitution reactions, the minor enantiomer is close to the limits of exact determination. Therefore, the influence of the alkyl residue on selectivity was investigated for less efficient (/ ,/ )- ,2-bis(dimethyl-amino)cyclohexane/i-BuLi (equation 11)°. On the base of the isolated corresponding... 

---