Diethyl amino phosphine

The la,5a-bridged compound (354) (a dithiolan) is converted by tris(diethyl-amino)phosphine into the derivative (355). °... 

The amino interchange reaction is another method commonly used for preparing phosphinous amides [67] (Scheme 9). The low boiling points of di-methylamine and diethylamine allow their displacement from Ar,AT-dimethyl and AT,iV-diethyl phosphinous amides, respectively, by other less volatile amines, leading to new members of the same class. High reaction temperatures are nevertheless required. 

This particular feature of P-N bond containing compounds can be utilized for synthetic purposes by using "phosphoryl protection" in the synthesis of amines based on alkylative procedures. The solution of this problem introducing two new reagents, i.e. diphenyl-phosphinic amide (I) and sodium N-(t-butyloxycarbonyl) diethyl phosphoroamidate (II) as useful synthetic equivalents of an amino moiety is the subject of this communication. 

DEHYDRO AMINO ACIDS Tfiphenyl-phosphine-Diethyl azodicaiboxylate. 

Many communications have concentrated on specific amino phosphonic acids or derivative types. Thus, esters of phosphonoaminoacetic add were obtained by the reactions between trialkyl (ethyl) phosphite and (218) and which are thought to proceed via the phosphorane (219). A sequence has been presented for the preparation of the mono- and di-benzyl esters of N-chz protected (a-aminoben-zyl)phosphonic acid. A synthesis of (aminomethylene)bisphosphonic acid from dibenzylamine, dibenzyl hydrogenphosphonate and triethyl orthoformate has been noted and the asymmetric hydrogenation of (220) in the presence of chiral phosphine catalysts yields samples of (221) with e.e.s of 63-96%. The pyrrolidine-based compound (222) has been prepared from methyl S)-N-methoxycarbonyl-4-oxo-2-pyrrolidinecarboxylate and iV-coupled 4-amino-butanal diethyl acetals were the starting materials in syntheses of the pyrrolidine-2-phosphonic add derivatives (223) in which Z represents the iV-protected amino add or peptide moiety. ... 

Mention might also be included here of the nature and potential importance of the choice of amino-protection and ester groupings in work on the aminophosphonic acids. The choice of groups for protection at nitrogen is obviously based on experience in conventional amino acid chemistry, and both r rr-butyloxycarbonyl (boc) and benzyloxy-carbonyl (cbz) groups are extensively employed. Most recorded syntheses of aminoalkyl-phosphonic and -phosphinic acids have relied on diethyl or dimethyl esters, largely as a consequence of the ready availability of the simple trialkyl phosphites and dialkyl hydro-genphosphonates the same esters are also preparable under mild conditions from the free acids by the action of ortho esters RC(OR )3 (R = H or Me, R = Me or Until... 

The reactions between methyl 4-oxopentanoate and phosphinic esters in the presence of ammonia yield the 4-amino-4-phosphinoylpentanoic acids (218) (synthesized as analogues of phosphinothricin), although difficulties may be encountered in the purification of these compounds so prepared ". The initial adduct formation between the ketones 219, ammonia and diethyl hydrogenphosphonate can be succeded by the conversion of the products (220) into pyrrolidine- and piperidine-2-phosphonic acids (Scheme 23). ... 

The strategy for the synthesis of phosphinate 54a or 54b involves the activation of the phosphoms atom into the P reactant, followed by successive reactions with a Michael acceptor (ethyl acrylate or diethyl maleate), dibromoethane, and an esterification using triethyl orthoformate. The incorporation of the amino acid group accomplished by nucleophilic substitution of the anion of the diethylaceta-midomalonate yielded the branched phosphinates in 50-77% yield. The final deprotected compounds were obtained in 11-21% yield after acidic deprotection and decarboxylation and they were purified by ion exchange chromatography. Compound 54b was synthesized by alkylation of the phosphonite intermediate with acetamidoacrylic acid, followed by acidic deprotection and ion exchange chromatography purification (Scheme 8). 

An inverse aqueous/organic biphasic approach for separation of catalyst and product is available with amphiphilic phosphines bearing amino groups. N-Bis (N, N -diethyl-2-aminoethyl)-4-aminomethylphenyl diphenylphosphine (N3P) was used in aqueous acidic media to modify and solubilize the palladium catalyst formed in situ from [PdCl2(PhCN)2] for hydrocarboxylation of 2-pentenoic acid to adipic acid [32]. Reaction carried out at 100 °C, pco = 50bar showed best... 

Polyhydroxypyrrolidine aza-sugar was synthesized starting from tri-O-benzyl-D-glucal 221. After steps, amino monoacetate 222 was prepared and it underwent C—N alkylative cyclization by the treatment of triphenyl phosphine and diethyl azodicarboxylate (DEAD) to produce flie corresponding polyhydroxypyrrolidine 223 in 88% yield (Scheme 40.45). 

To a solution of imino-phosphine 3 (7.8 g, 15.7 mmol) in THF (40 mL), n-BuLi (9.8 mL, 15.7 mmol) is added dropwise at -80°C. The reaction mixture is allowed to warm to room temperature. After 1 h at room temperature, the solution is cooled to -78°C and one equivalent of HSiCls (1.6 mL, 15.7 mmol) is added dropwise, and the solution is allowed to warm to room temperature. Then, all the volatiles are removed under vacuum, and the residue is extracted twice with diethyl ether (2 x 50 mL) and once with dichloromethane (30 mL). After removal of solvents under vacuum, the residue is washed with pentane to give a pale yellow powder of phosphino(amino)dichlorosilane 4. Yield 7.8 g (83%), Mp 170-171°C. 

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