Unsaturated compounds amides

Cholesterol as well as unsaturated or saturated hydrocarbon chains are used as lipophilic lipid anchors. Although Cl 8-hydrocarbon chains (oleoyl or oleyl unit) are only used in unsaturated compounds, structural variations with C14-, C16-, or even Cl 8-hydrocarbon chains in saturated compounds are known (27). The lipophilic units are linked with a parent structure (usually glycerol) via ether (e.g., DOTMA) or ester bridges (e.g., DOTAP). Ester bridges are often used to create the linkage to avoid cytotoxicity, because ether bonds are more difficult to break down biologically than ester bonds (58). Substances that are easy to decompose and are therefore often used as a spacer are carbamate units (29) [e.g., 3p-[A-(A, A -dimethylaminoethyl)carbamoyl]-cholesterol (DC-Chol)], amide units, or phosphate esters. However, a direct correlation between toxicity and the... 

In general, the reaction of unsaturated 5(4//)-oxazolones 497 with nitrogen nucleophiles effects ring opening to give the corresponding unsaturated acylamino amides 498 (Scheme 7.158). Depending on the nucleophile, for example, amines, hydrazines, oximes, and so on, the products obtained can be cyclized and this process allows the synthesis of a wide variety of new heterocyclic compounds. 

The other stereoselective synthesis/281 shown in Scheme 8, foresees conversion of Boc-L-Asp-OtBu 20 into the related (3-aldehyde 22 via the Weinreb amide 21 and its reduction with diisobutylaluminum hydride (DIBAL-H). Wittig condensation of 22 with the ylide derived from (3-carboxypropyl)triphenylphosphonium bromide using lithium hexamethyldisilaza-nide at —78 to 0°C, produces the unsaturated compound 23 which is catalytically hydrogenated to the protected L-a-aminosuberic acid derivative 24. Conversion of the co-carboxy group into the 9-fluorenylmethyl ester, followed by TFA treatment and reprotection of the M -amino group affords Boc-L-Asu(OFm)-OH (25). 

The 1,2-diaminopyridinium salts also react with a,/)-unsaturated compounds with the loss of the alkene or alkyne fragment to give 2-substituted triazolopyridines (37),50 and with ethyl Af,fV-diethyloxamate to give the amide 38.51... 

The second variant of this method uses a,/(-unsaturated Weinreb amides as electrophiles1066,1076 1077. The 1,2-addition of compound 740 to the amide 742 gave the ketone 743, which underwent spontaneous Nazarov cyclization upon work-up1077... 

The Af-acylenamines and their precursors bis-amides 9 are used as amidoalkylation reagents5,6. The main purpose of the latter is to produce the Af-acyliminium ions 2 which act as highly reactive electrophilic reagents3. Consequently, the application of N-acyliminium ions 2 considerably extends the preparative possibilities for functionalization of aromatic, heterocyclic and unsaturated compounds. 

Reactions of /V-Sulfinyl Amides with Unsaturated Compounds... 

Summary Treatment of geminal silyldiamines with monohalo silanes leads to the formation of 1-amino-1,3-disilazanes. Mono-NH-SiF-functional cyclodisilazanes can be isolated by ring closure of their lithium derivatives in the reaction with trifluorosilanes. Lithium salts of these cyclodisilazanes react with H-acidic compounds like alcohols as amides and with unsaturated compounds like aldehydes as silaimines. 

The reaction of a silylacetate derivative with an aldehyde or ketone was initially studied by Rathke and Yamamoto. Rathke and coworicers studied the addition of the lithium anion of r-butyl (trimethylsi-lyl)acetate (340) with a variety of aldehydes and ketones (equation 78). The anion can be formed directly from the silyl compound on treatment with LDA. The reaction proceeded to give the conjugated alkenes in excellent yields. Unsaturated compounds reacted via 1,2-addition. No discussion of alkene geometry was present. In the Yamamoto work, the ethyl (trimethylsilyl)acetate derivative (342) was used in a variety of reactions with aldehydes and ketones (equation 79). The anion was formed wiA dicyclohexyl-amide in THF. It was stated in the experimental section that the ( ) (Z) ratios of alkenes were dependent on the reaction conditions. In all the examples presented in this work, the ( )-isomer was predominantly formed. 

A number of syntheses of 2-pyrazolin-5-ones depend on the reaction of compounds, other than /3-ketoesters, substituted in the /3-position or of a,/8-unsaturated acids, esters and amides. The most frequently used unsaturated compounds are those having a triple bond in the apposition.1023,1024,1075,1548,1680 R2 can be HO,1552 RO1023,1024,1686 or H2N (eq. 8).1023,1024 A similar reaction is the condensation of ethyl... 

When saturated alkyl halides were used in place of allyl compounds, a zinc/cop-per couple or zinc dust/copper iodide promoted the 1,4-addition to a-enones or a-enals. Sonication enhanced the efficiency of the process leading to the 1,4-adducts in very good yields [166]. This reaction was later extended to various a,j3-unsaturated compounds such as esters, amides and nitriles [167]. The reactivity of the halide followed the order tertiary > secondary primary and iodide > bromide > chloride making the assumption of a radical process highly probable [168]. 

Preparation of Phosphines by Addition of P-H to Unsaturated Compounds. -This route has not received much attention over the past year. A stereoselective synthesis of tris(Z-styryl)phosphine is offered by the addition of phosphine to phenylacetylene in a superbasic system (HMPA-H20-K0H)." In a similar vein, the reaction of phosphine with styrene and a-methylstyrene in a superbasic medium (DMSO-KOH) provides a route to the primary phosphines, (2-phenylethyl)phosphine and (2-methyl-2-phenylethyl)phosphine, respectively. 7 Transition metal phosphine complexes have been shown to catalyse the a-hydroxylation, P-cyanoethylation, and P-alkoxycarbonylethylation of phosphine. 71 Addition of primary phosphines to acrylic esters has been used for the synthesis of the phosphines (80).7 A similar addition of diphenylphosphine to acrylic esters and amides has given a series of hydrophilic phosphines (81). 72 The bis(phosphorinanyl)ethane (82) is formed in the photochemical addition of l,2-bis(phosphino)ethane to 1,4-pentadiene. ... 

Write out in the form of a table the behavior of unsaturated compounds, hydrocarbons, acids, alcohols, aldehydes, ketones, ethers, esters, anhydrides, amines, amides, and halogen compounds with the following reagents water, cold solution of sodium hydroxide, hot solution of sodium hydroxide, dilute hydrochloric acid, cold concentrated sulphuric acid, acetyl chloride, sodium, bromine, solution of sodium carbonate, and phenyl-hydrazine. 

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