Cesium triethylamine

Another example where PEG played the role of polymeric support, solvent, and PTC was presented by the group of Lamaty [72]. In this study, a Schiff base-proteded glycine was reacted with various electrophiles (RX) under microwave irradiation. No additional solvent was necessary to perform these reactions and the best results were obtained using cesium carbonate as an inorganic base (Scheme 7.64). After alkylation, the corresponding aminoesters were released from the polymer support by transesterification employing methanol in the presence of triethylamine. 

CO/H2 (1 1) and 230°C. A comparison between Figure 1 and Table I highlights the strong similarity between cesium and triethylamine as... 

The synthesis of phosphino sulfoximine 97 relied significantly on the successful development of methods pursued in parallel in our group. Whereas palladium-catalyzed cross-couplings between 53 and 98 proceeded in low yield, the copper catalysis with a combination of copper(l) iodide and cesium acetate worked well, affording 99 in up to 83% yield [78]. The resulting phosphine oxides 99 were then reduced to the corresponding phosphines 97 using a mixture of trichlorosilane and triethylamine (Scheme 2.1.1.33). 

Aminomethylated polystyrene (DVB I %, 1.07 mmol Trifluoroacetic acid / dichloromethane (I/I, v/v), 10mL 3-Bromopropionic acid (97 %) (158 mg, I mmol) Cesium carbonate (99.9%) (652 mg, 2 mmol) Triethylamine Benzene Acetone... 

Using an analogous procedure, 2-(trifluoromethyl)-l,3-dioxolan-2-amine and -l,3-dithiolan-2-amine can be converted into the corresponding iminosulfur difluorides 5 cesium or sodium fluoride may be used as the base but the highest yields (ca. 80%) are obtained in the presence of triethylamine.199... 

Acid scavenger.3 Cesium fluoride is recommended as a scavenger for HF and HBF4 in place of triethylainine in reactions involving base-sensitive substrates. An example is the esterification formulated in equation (I). No racemization occurs in the transesterilication of equation (11), although it is extensive when triethylamine is used. 

Dehydrohalogenation Alumina, see Sulfur tetrafluoride. Alumina-Potassium hydroxide. Cesium fluoride. l,5-Diazabicyclo[4.3.0]nonene-5. l,4-Diazabicyclo[2.2.2]octane. 1,5-Diazabicyclo[5.4.0]undecene-5. Dimethylaminotrimethylstannane. Dimethyl sulfoxide. Hexamethylphosphoric triamide. Lithium chloride. Lithium dicyclohexylamide. Magnesium oxide. Potassium r-butoxide. Potassium fluoride. Potassium triethylmethoxide. Pyridine, see Nitrosyl chloride. Silver fluoride. Silver nitrate. Sodium amide. Sodium bicarbonate, see Nitryl iodide. Sodium isopropoxide. Triethylamine, see Sulfur dioxide. 

Alkenylations can also be carried out the optimum conditions for 2-bromopropene with palladium acetate include the use of triphenylarsine with silver carbonate and triethylamine, but the advantages over more amenable conditions, using triphenylphosphine with potassium or cesium carbonate, are marginal. ... 

A differently anchored Mukaiyama reagent is the N-methylpyridinium iodide salt 57 [71], which has been obtained by reaction of the Merrifield resin with N-Boc-aminocaproic acid in the presence of cesium carbonate to give the supported ester 55 (Scheme 7.19). Further Boc-deprotection and reaction with 6-chloronicoti-noyl chloride in the presence of Hxinig s base furnished the anchored 2-chloro-pyridine 56, which was transformed into the final N-methylpyridinium salt 57 after N-methylation in neat methyl iodide. This supported reagent has been used in the rapid microwave-assisted esterification of carboxylic acids and alcohols in the presence of triethylamine as base, with dichloromethane as solvent at 80 °C, the products being obtained in high purity after simple resin filtration [72],... 

Oxalyl-CPG is obtained by reacting oxalyl chloride and 1,2,4-triazole with a 3 -hydroxyl nucleoside and LCAA-CPG. Cleavage of the oxalyl linker can be effected by a variety of mild reagents including triethylamine, propylamine-DCM, 5% ammonium hydroxide in methanol, or 0.5 M cesium fluoride in methanol for 15 min. Alternatively, 0.5 M DBU in either pyridine, dichloromethane, or dioxane was shown to effect full cleavage of the oxalyl linkage in less than 30 min at room temperature [111]. 

The resin-bound fragment preparation starts with the chlorine displacement from the chloromethylene function on a chloromethylated polystyrene by the cesium salt of Z-L-Cys(Tr)-OH. The resulting benzyl ester is treated with Scm-Cl to form the active intermediate sulfenyl thiocarbonate which is allowed to react with 4-acyloxy-6-mercaptodibenzofuran, preferably in dichloromethane-hexafluoro-2-propanol, with or without catalytic triethylamine (eq 16). ... 

The last three steps can either afford linoxepin or Ao-linoxepin depending on the type of base used in the second Heck reaction. The last syn-p-hydride elimination of the more accessible p-hydrogen appears to be favored by the use of triethylamine, while cesium acetate delivers the more conjugated product supposedly via the palladium enolate. 

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