Bis , secondary

Studies on the biosynthesis of prostaglandins revealed that a strained bicyclic bis(secondary-alkyl) peroxide was not only a key intermediate, but could survive the biological conditions long enough to be isolated, albeit in minute amounts. This was a startling discovery in that no simple bicyclic peroxides of the same type were known, clearly for reasons of preparative difficulty. The prostaglandin connection focused attention upon this missing class of peroxides and stimulated... 

A bis(secondary/tertiary) ligand reacted with diphenylzinc to afford the bis(phenylzinc) complex 88 (Scheme 67).148 The unusual reactivity of this dinuclear species was demonstrated by its interactions with trimethylphosphine oxide and iV,A-dimethylacetamide. In both cases, the products contained eight-membered rings incorporating both zinc atoms the structure of the bis(trimethylphosphine oxide) product is shown in Figure 46. 

The resultant material (isolated in low yield) is an intriguing tricyclic system that could be viewed as an overall antiaromatic system or as two aromatic rings with two phosphorus sites connecting them. In any event, this tricyclic product readily undergoes addition of water in even trace amounts to generate a bis-secondary phosphine oxide (Equation 4.26). 

Giovenzana GB, Tron GC, Paola SD, Menegotto IG, Pirali T (2006) A mimicry of primary amines by bis-secondary diamines as components in the Ugi four-component reactionlS. Angew Chem 118(7) 1117-1120... 

Allylic bis-secondary y/c-diols are converted into 1,3-dienes in 80-98% yield under the same conditions. The reagents also effect conversion of allylic alcohols into 1,3-dienes under these conditions (75-90% yield).4. 

Furthermore, a widely used class of degradable polymers based on acrylate esters are polyamino esters (PAE). These are both efficient gene carriers with an advantageous degradation profile and low cytotoxicity and also easy to synthesize [79, 80] by conjugate addition of either primary or bis(secondary amine)s to different diacrylate esters [81-87]. 

Nortrilobine (500), C34H32N205, mp 177-180°C (MeOH), [a] 5 +216° (c 0.44, CHC13), from Pachygone ovata Miers ex Hook. f. Thoms. (Menispermaceae), is the first bis-secondary dibenzo-p-dioxin bisbenzylisoquinoline alkaloid. It was examined by... 

Linear poly(amido-amine)s are obtained by polyaddition of primary monoamines, or bis-(secondary amines), to bis-acrylamides38 44). 

When a Mannich reaction is carried out between a substrate containing at least two active hydrogen atoms and a primary or a bis-secondary amine, a polycondensation takes place with production of a polymeric derivative. Fhe polycondensation can also occur when both an NH group and one active hydrogen atom arc present in the same molecule. The reaction product is thus characterized by the presence of the methylene moiety, whieh is derived from the formaldehyde, and forms the polymer backbone, with the consequent possibility of polymer degradation by deamination or dcaminomethy-lation both of these reactions are typical of Mannich bases (Chap. II, A). 

Angeloni, A. S Ferruti, P and Laos, M Mannich bases in polymer synthe.sis. 7, lY)ly(N-aminomeihyleneamides) by polycon-densalion reaction of bis Mannich bases of dicarboxyamides with bis secondary amines. Polymer Common., 25, 119, 1984. 

Another synthesis of diphosphiranes was described by Stelzer via deprotonation of the bis-secondary phosphines with strong organic bases in the presence of CuCl and pyridine (Equation (7)) <90CB653>. 

The most popular lands of the diols for asymmetric synthesis are bis-secondary diols that have a C2 axis of symmetry [212]. The presence of the symmetry axis avoids the formation of diastereoisomeric esters or acetals [213], (1R, 27 )-Cyclohexanediol 1.34 (n = 1) has been used as an auxiliary in asymmetric cyclopropanation [214] and (IS, 2S)-cycloheptanediol 1.34 (n = 2) in 1,4-addition of cuprates[157], Dioxolane derivatives of 1.34 have been used for asymmetric P-ketoester alkylations [215] and cuprate 1,4-additions [216]. Linear 1,2-diols 1.35 (R = Me, i-Pr, c-CgH j, Ph) and functionalized 1,2-diols 1.36 (Y = COOalkyl, CONR 2, CH2OR ) are readily available from optically active tartaric acids 1.36 (Y = COOH). Acetals derived from these diols are valuable reagents m asymmetric synthesis [173, 213, 217], as the related 1,3-diols 1.37. Acetals of 1,3-butanediol 137 (R = Me, R = H) have also been used. When these acetals are formed from aldehydes under thermodynamic conditions, one 1,3-di-oxane stereoisomer often predominates. In this favored isomer, the substituent from the aldehyde and the methyl group from 1.37 are both in equatorial orientar... 

Scheme 5.22 Working hypothesis of the split Ugi reaction of bis-secondary amines.

Reaction of the crab-like starting material with a bis-secondary amine gave a 1 1 cycloadduct where each terminal amine reacted with the alkyl chloride function on the ends of the crab-like reactant. In one case, a tris secondary amine was reacted to give a peraza-crown with a secondary amine substituent (Krakowiak et al., 1989b). The functional group also can be attached to a... 

A similar method (E-3) was used to prepare allyloxymethyl-substituted A,N -dialkyldiaza-18-crown-6, except using a bis secondary amine starting material rather than the bis primary amine (Bradshaw et al., 1988a). Some... 

The cyclization reaction of dihalogen or ditosylate compounds with bis primary or bis secondary amines is similar to the diacid dichloride reaction except that the diaza-crown is obtained in a single step. This is a convenient procedure particularly since the dihalide is usually readily available and inexpensive. This cyclization process does not need high-dilution techniques because of template effects by metal ions. It is important to note that when using a bis primary amine and a dihalide, many side products such as the cryptands and bis-crown ethers can be formed (Alfa et al., 1988 Krakowiak and Bradshaw, 1991). 

Formation of two C—N bonds by a 1 1 cyclization reaction of a bis secondary amine and a dihalide or a ditosylate. The N,N -dialkyl-substi-... 

D. RING CLOSURE TO FORM TWO C—N BONDS BY A 1 1 CYCLIZATION OF A BIS SECONDARY AMINE WITH A DIHALIDE OR DITOSYLATE... 

Terminal bis secondary amines can be cyclized with dihaloalkanes. There could be some template affect by alkali metal cations in the cyclization step even though the log K for the association of the alkali metal ions (except lithium) with a cyclic amine is low. In the building-block method to form the polyaza-crowns (methods 0-1 and 0-2), sodium, or potassium carbonate... 

Other polyaza-crowns have been prepared by reacting the crab-like bis-a-chloroamides with bis secondary amines. As shown in methods 0-7 and... 

R=2,4,6-Bu2C H2) reacts with water at elevated temperatures to form the bis ( secondary phosphine oxide) (192). Treatment of the 1,4-phosphabutadiene (193) with molybdenum-or tungsten-carbonyl complexes gives the metalladiphosphapentadienes (194) Routes to the P=C=N system (195) have been described, together... 

Substituted derivatives of imidazo[4,5-h]quinoxaline have also been obtained. The l-methyl-2-iminoquinoxaline 66 reacts with triethyl orthoformate to give 4-methylimidazo[4,5-i)]quinoxaline (67), and the 4-methyl-2-oxo derivative 68 is produced by reaction of 66 with urea. The bis(secondary amine) 69 on reaction with acetyl chloride in di-methylacetamide affords the imidazo[4,5-fe]quinoxalinium salt 70, °... 

FIGURE 27 Schematic formation of D3-symmetrical lanthanide triple-helical precursors with (A) 2,6-bis(tertiary-amide)pyridine ligands and (B) 2,6-bis(secondary-amide) pyridine ligands. The representation of the complexes corresponds to the crystal structures of [Eu(L18 )3] and [Eu(L18T] (redrawn from Le Borgne et al., 2003 Renaud et al., 1997a). 

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