Lead tetraacetate with amines

Oxidation of C9-Amine (3) with Lead Tetraacetate. C9-Amine hydrochloride (53 mg., 0.17 mmole) was dissolved in 0.1 ml. of water and 5 ml. of acetic acid and to the solution was added lead tetraacetate (190 mg., 0.3 mmole) at 16°-18°C. in 10 minutes. Insoluble material was removed by filtration, and the filtrate was dried by lyophilization. The residue was dissolved in 5 ml. of water and the solution was placed on a column of Amberlite CG-50 (ammonium form, 1 x 10 cm.) followed by a similar treatment as described in the case of periodate oxidation. N-Cyano derivative (5.1 mg.) was obtained and proved to be identical with the N-cyano derivative obtained from the periodate oxidation. 

Morpholiaoglucopyranosides have beea syathesized from sucrose by selective lead tetraacetate oxidatioa of the fmctofuranosyl ring to a dialdehyde (6). This product was subjected to reductive amination with sodium borohydride and a primary amine such as benzylamine to produce the /V-henzy1morpho1ino derivative (7) (99). 

Phenylpftenanttirldlne (3).3 Amine hydrochloride 1 (2.72 g, 9 28 mmol) in EtOH (75 mL) was treated with 0 926 N cold solution of KCXI. Colorless crystals appear The mixture was shaken lor 30 mtn in ice, water was added and the product was filtered and dryed (PaOs) to afford 2.7 g of 2 (100%), rnp 102°C (hexane) 2 (2 0 g, 6 6 mmol) in anh pyndine (20 mL) was treated with an excess of NaOCHa (exothermc) Alter 20 h the solvent was removed In vacuum, the residua triturated with EtaO and the extract treated with dry HCI to obtain the hydrochlonda of 3, mp 107-108°C (from petroleum ether), mp 95-100° (Irom water) Olphenylmethyieneanlllna (5). To a suspension of lead tetraacetate (4.9 g, fO mmol) in PhH (100 mL) under Na was added a solution of tnphenyhnethylamine 4 (2 6 g, 10 mmol) in PhH (100 mL) dropwise under stirring The mixture was refluxed for 1 h, cooled, filtered, washed and the solvent evaporated The residue was crystallized from EtOH to give 2 2 g of 5 (85%), mp 111-112°C. 

The oxidation of certain steroidal <5,e-unsaturated amines with either N-chlorosuccinimide or lead tetraacetate yields bridged aziridines, see structure (117)... 

The Cg-amine, originally obtained by the methanolysis of kasugamycin, on treatment with lead tetraacetate or sodium periodate afforded a nitrile amine, with evolution of carbon dioxide, showing a maximum at 2200 cm.-1. This reaction is explained only by the structure (13). The -N-C=N group of the product can be formed by oxidative decarboxylation and can be easily rationalized by the present understanding of such reagents (2, 13) as shown below. On the other hand, the treatment... 

The analogue, t-butyl methyl iminodicarboxylate 25, is obtained by the reaction of methanol with t-butyl oxamate (24) in the presence of lead tetraacetate. Its stable non-hygroscopic potassium salt is converted into alkyl derivatives 26 by the action of alkyl halides such as butyl bromide, allyl bromide, propargyl bromide and ethyl bromoacetate. The products are hydrolysed by trifluoroacetic acid to salts of primary amines, whereas... 

The spiroacetal morpholine work of Scheme 38 subsequently inspired research on the preparation of a novel family of morpholino-glycosides from sucrose via lead tetraacetate cleavage and reductive amination (Scheme 40). Significantly, the latter work, which was done with the present author, unveiled a completely new structural class of sweeteners, more intense than sucrose but having a similar taste profile. 

Phthalimidonitrene 348 is derived by reaction of the corresponding amine 347 with lead tetraacetate in chlorobenzene (Scheme 4.72) [404]. Addition to Cgg affords mono and multiple adducts with up to four phfhalimido addends. 

Treatment of the peroxidic solutions with MnOa or lead tetraacetate resulted in the evolution of 02 up to 50% of that consumed in the photosensitized reaction and in the formation of NH3 and aldehydes.82,281 Thus, isobutyl amine (434) gave rise to isobutyraldehyde... 

A method of preparation of wide applicability is the oxidation of hydroxyl-amines with such diverse reagents as bromine water, hypobromide ions, dichromate ions, lead tetraacetate, peracids, and ferric chloride (Eq. 5). 

A similar reaction can be effected by the treatment of amides with lead tetraacetate.2 4 In this case the initial isocyanate and the amine formed from it react with the acetic acid liberated from the lead tetraacetate to give, respectively, ureas and amides. If the reaction is carried out in the presence of an alcohol, carbamates are formed (6-8). 

Primary amines at a primary carbon can be dehydrogenated to nitriles. The reaction has been carried out with a variety of reagents, among others, IF5,"9 lead tetraacetate, 20 nickel peroxide,121 NaOCl in micelles,122 S g-NiSO, 2-1 and CuCl-02-pyridine.124 Several methods have been reported for the dehydrogenation of secondary amines to imines.125 Among them126 are treatment with(l) iodosylbenzene PhIO alone or in the presence of a ruthenium complex, 27 (2) Me2SO and oxalyl chloride, 2" and (3) f-BuOOH and a rhenium catalyst. 29... 

Two closely related mesoionic systems, 59 and 60, were obtained by reductive cyclization of 61 with TEP,62 and by oxidation of 62 with lead tetraacetate,63 respectively. The pyrazolo[4,3-c]pyrazole 64 was obtained from the azo compound 63 by reduction with dithionite, followed by diazotization of the resultant amine and cyclization with... 

Direct amination of quinoxalinones with hydroxylamine-O-sulfonic acid produces the 1-amino derivatives (135) in 70-80% yield, and subsequent oxidation with lead tetraacetate gives the 1,2,4-benzotriazines (138). Benzotriazine formation probably involves the formation of an intermediate nitrene (136), ring expansion to a benzo-triazepinone (137) and subsequent loss of carbon monoxide. The nitrene (136 R = Ph) was trapped as the sulfoximide 139 when the oxidation was carried out in the presence of dimethyl sulfoxide.147... 

Aziridinyl ketones can be synthesized from unsaturated carbonyls using a series of other methods. For example, azabicyclo[4.1.0]heptanone 27 was obtained from cyclohexenone 25 in its reaction with TV-bromotoluenesulfona-mide sodium salt 33 [49] (Scheme 1.10). The reaction of chalcone with N-chlorotoluenesulfonamide in the presence of silver nitrite is described in [50]. Trans-Aziridinyl ketone 18 was synthesized by reacting chalcone 22 with N,N-diamino-l,4-diazoniabicyclo[2.2.2.]octane dinitrate 34 and sodium hydride in 2-propanol [30, 51]. Aziridinyl ketones can be obtained in the reaction of a -unsaturated ketones with A,A-dichlorosulfonamines [52] and with amines in the presence of lead tetraacetate and trifluoroacetic acid [53] or in the presence of triethylammonium acetate under electrochemical reaction conditions [54]. 

An a-hydroxy tertiary amine is oxidized with difficulty. At 60°, however, 2-(7V, Ar-diethylamino)ethanol took up lead tetraacetate, but scission occurred between the carbon-nitrogen bond (instead of between the carbon-carbon bond), possibly by a free-radical mechanism.196... 

Reaction of triphenylarsane with lead tetraacetate lead to the formation ofPh3As(OAc)2 (21, 34, 71). This compound reacts with amines to give Ph3As=NR ... 

When a mixture of aminocycloheptatriazolones 52 and 53 (prepared by amination of 6//-cycloheptatriazol-6-one) was treated with lead tetraacetate in the presence of cyclic... 

Barton oxidation was the key to form the 1,2-diketone 341 in surprisingly high yield, in order to close the five-membered ring (Scheme 38). The conditions chosen for the deprotection of the aldehyde, mercuric oxide and boron trifluoride etherate, at room temperature, immediately led to aldol 342. After protection of the newly formed secondary alcohol as a benzoate, the diketone was fragmented quantitatively with excess sodium hypochlorite. Cyclization of the generated diacid 343 to the desired dilactone 344 proved very difficult. After a variety of methods failed, the use of lead tetraacetate (203), precedented by work performed within the stmcmre determination of picrotoxinin (1), was spectacularly successful (204). In 99% yield, the simultaneous formation of both lactones was achieved. EIcb reaction with an excess of tertiary amine removed the benzoate of 344 and the double bond formed was epoxidized with peracid affording p-oxirane 104 stereoselectively. Treatment of... 

Many reagents convert primary amines into nitriles. Some of these have been mentioned above and represent serious limitations on methods for generating carbonyl compounds. Other ways of oxidizing amines to nitriles are the use of nickel peroxide,lead tetraacetate," copper(I) chloride plus oxygen and pyridine," iodine pentafluoride and benzeneseleninic anhydride. double bromination-dehy-drobromination can be effected for the preparation of nitriles with 2 equiv. of NBS and trimethyl-amine. Likewise, fluorination and elimination of HP gives nitriles." ... 

Hofmann rearrangements Primary amides are converted into amines in high yield by reaction with this owdant at room temperature in aqueous acetonitrile (equation I). The reaction is rslated to a recent method using lead tetraacetate (6, 316) however, the intermet iate isocyanate in this case is not trapped as the carbamate, but is hydrolyzed alirectly to the amine. 

The direct oxidation of the tr-adduct 1 with bromine, A -bromosuccinimide or, preferably, lead tetraacetate in the presence of acetic acid afforded jS-acetoxy amines 2 by an overall syn addition. The acetate reduction with lithium aluminum hydride gave the corresponding )S-hy-droxy amines 360 62. 

Vicinal diamines, e.g., 5, were formed as byproducts in the oxyamination of terminal alkenes with excess amine and lead tetraacetate, but were exclusively obtained when the oxidant is bromine, 3-chloroperoxybenzoic acid, or, V-bromosuccinimide64. 

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