Carbon suboxide, reaction with

Published sources do not mention any dangerous reactions with carbon suboxide, which is hardly ever used. 

Anils, reaction with carbon suboxide, 634 Anisaldehyde, 609... 

Figure 3-14 shows an induction period in the reaction of carbon suboxide (O=C=C=C=0) with triethylamine. This reaction is complex and is not yet... 

The first synthesis of derivatives (77) of pentatetraene-carboxylic acid has been reported using a Wittig reaction of 1-H-allene-l,3-dicarboxylate monoester chlorides (76) in the presence of triethylamine.60 In one case an intermediate was obtained and was converted to (77) by further treatment with base. The reaction of carbon suboxide with phosphonium ylides has also... 

Reaction of urazoles 359 with carbon suboxide in dilute solutions (dioxane-MeCN 1 1, acetone, MeCN) provides 360, while in more concentrated solutions small yields (<25%) of 361 are also obtained (Scheme 54) <1995H(41)303>. 

Thiolactams 622 treated with carbon suboxide provide mesoionic compounds 623. Their 1,4-dipolar cycloaddition reaction with highly reactive PTAD gives compounds 624, formed by the cycloaddition followed by extrusion of COS, in quantitative yield (Scheme 100) <1995T6651, 1995H(41)1631>. 

A promising new method for the preparation of thiobarbituric acids (112) involving the reaction of carbon suboxide with various arylthio-ureas was reported by Baranova et al.2il... 

The heteroaromatic betaine (110) is formed in the reaction of 4,6-dimethyl-2-methyl-aminopyrimidine (234) with carbon suboxide (73JOC3485). 

A very promising procedure deserves to be mentioned, the reaction of carbon suboxide (592) with hexamethyldisilazane (595)216 which affords in the first step 2,4-dioxo-6-trimethylsiloxy-l-TMS-l,2,3,4-tetrahydro-3-pyridine[N,N-bis(TMS)-car-boxamide] (395) or an isomer of 395 that can directly be converted to yield a variety of piperidine (397, 398, 400) and pyridine compounds (399a, 399b). 392 and 394... 

Hydroxy-2H-pyranones-2. These heterocycles are formed on reaction of si-lyl enol ethers with carbon suboxide in ether at — 20 - 250.1... 

Pyrimidino[l,5]diazepin-2,4-diones are formed by the treatment of 1,2-diaminopyrimidines with carbon suboxide <95H(4l)303>. The reaction may be extended to the formation of... 

Benzoylacetone reacts with carbon suboxide in the presence of sulfuric acid as a catalyst yielding a mixture of pyranopyran derivatives (383) and (384) <67M243l>. In a related reaction, malonyl... 

Liuti et used a discharge flow system coupled to a time of flight mass spectrometer to measure the kinetics of the reactions of carbon suboxide with O atoms. They obtained the following values for the rate coefficients at room temperature ... 

Hillhouse and co-workers discovered a new route to carbyne complexes which is based on the reverse of carbyne-carbonyl coupling (J72). Reaction of complex 200 with carbon suboxide affords the ketenyl complex 201 [Eq. (159)]. Formation of the ketenyl ligand in 201 was postulated to arise from attack of phosphine on an intermediate ketenylidene complex. Warming of complex 201 results in cleavage of the ketenyl ligand and formation of the phosphonium carbyne complex 202. This mechanism was put to work in a more direct fashion by reaction of complex 200 with PhjPCCO [Eq.(160)]. 

NHC(0)R 149). Malonic acid reacts with SF5NCO at BO C to give both the amide acid, SF5NHC(0)CH2C00H, and the diamide, SFsNHC(O)-CH2C(0)NHSF5 149). This diamide is also obtained from the reaction of SF5NH2 with carbon suboxide 149). 

Miscellaneous Routes. Polyamides have been prepared by other reactions, including addition of amines to activated double bonds, polymerization of isocyanates, reaction of formaldehyde with dinitriles, reaction of dicarboxylic acids with dllsocyanates, reaction of carbon suboxide with diamines, and reaction of diazlactones with diamines. These reactions are reviewed in Reference 4. 

The reaction of carbon suboxide with 2-aminooxazoles, which are... 

P) +Carbon Suboxide. The reaction of 0( P) with carbon suboxide is rather unique in that three identical molecular species are formed in the same reaction, 0( P) + C302(A" 2 )- 3CO(A 2 ). Although apparently spin forbidden, the reaction takes place veiy rapidly. The spin-conserved process yielding CO2 + C2O has been shown to be negligible (<0.4%). ° The mechanism of the reaction has been proposed to be ... 

The major pathway to 3,4-dihydro-2/f-l,5-benzodioxepin-2-ones (140) is the Baeyer-Villiger oxidation of flavanones (139) <91SC2263>. Reaction of catechol with carbon suboxide gave benzo-dioxepindione (141) <90MI 9l2-02>. 

Isomeric amino alcohols (83 X = O, Y = NH X = NH, Y = O) react with carbon suboxide to form positional isomers (65) and (66), each in ca. 50% yield, together with lower yields of malonic acid derivatives (Equation (29)) <92G485>. Similarly, carbon suboxide is reported to react with hydroxyimines to afford mesoionic derivatives 67) in 9-14% yield <84H(22)2587>, although, as discussed above, others have questioned the outcome of these reactions <82CC1328,85JHC157>. 

H. Niki, E. E. Daby, and B. Weinstock, Chemiionization in the room-temperature reaction of carbon suboxide with atomic hydrogen and oxygen, paper presented at the 156th National Meeting of the American Chemical Society, Atlantic City, September 1968. 

The nucleophilic reactivity of the thiocarbonyl sulphur atom in alkyl dithiocarbamates has been confirmed by Russian workers, who obtained the malonic acid derivative (324) from the reaction of carbon suboxide with twice the theoretical amount of alkyl dithiocarbamate. The same... 

Reactions of carbon suboxide with oxo compounds 5-Alkylidene-l,3-dioxane-4,6-diones from aldehydes Furans from y-diketones... 

The polymerization of carbon suboxide can theoretically be initiated by a ketene like dimerization of the molecule. However, it was shown that the polymerization is induced by trace amounts of nucleophiles, such as water, to give pyrone derivatives, which react with more carbon suboxide to form poly(a-pyrone). Although most reactions of carbon suboxide seem to be initiated by nucleophilic reactions, some cycloaddition reactions of carbon suboxide are known (see Section 3.1.2.2). 

The complex has a strong ketene absorption at 2080 cm A similar reaction occurs when (PPh3)2Pt02 is treated with carbon suboxide to give the [2+1] cycloadduct 14. 

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