Dihalides from amines

One of the characteristic features of the metal-bis-acetylide complexes in chemical reactions is that they undergo a ligand exchange reaction with metal dihalides in amines in the presence of a cuprous halide catalyst to produce a monoalkynyl-metal-monohalide complex (Eq. IS) which results from selective cleavage of the metal-carbon bond weakened by the /ram-alkynyl group in the bis-acetylide... 

Iminophosphoranes can also be used to synthesize symmetrical carbodiimides. In this case they are reacted with carbon dioxide, thereby mimicking the synthesis of carbodiimides from amines and carbon dioxide. Another useful synthesis of unsymmetrical carbodiimides, not requiring the use of carbonyl chloride, is the reaction of carbonimidoyl dihalides with amines. The synthesis and chemistry of carbonimidoyl halides was reviewed in 1968. ... 

Cupric chloride nitrosyl 1,1-Dihalides from prim, amines... 

Dialkylation of an amine or sulfonamide with a 1,3-dihalide provides a further route to azetidines <79CRV33l, 64HC( 19-2)88 5). Examples of this approach are the formation of N-tosylazetidine from tosylamide and l-bromo-3-chloropropane and the formation of N-alkylazetidinyl esters (36). The latter reaction works well except for R=Me the former provides a useful route to azetidine since the tosyl group can be removed by reductive methods. 

Although systematic investigations are lacking, alkyl chlorides or alkyl bromides and tellurium do not lead to isolable dialkyl tellurium dihalides. Cyclohcxyl bromide and tellurium reacted at 160°, but dicyclohexyl tellurium dibromide could not be isolated from the reaction mixture4. However, when the reaction was carried out in the presence of an amine, dimethylformamide, or dimethyl sulfoxide, adducts of dicyclohexyl tellurium dibromide were obtained in approximately 50% yield4. 

The first documented synthetic macrocycle was synthesized by Baeyer via the condensation of pyrrole and acetone in the presence of mineral acid (Baeyer, 1886). Other examples, from a historical point of view, are listed in a review by Newkome and coworkers (Newkome et al., 1977). The aliphatic macrocycles were synthesized later as exemplified by Willstatter s synthesis of eight-membered rings (Willstatter and Veraguth, 1905) and Ruzicka s studies of the chemistry of muscone and civetone (Ruzicka, 1926). The synthesis of thiacycloalkanes using the reaction of sodium sulfide with an alkyl dihalide was also investigated early in the twentieth century (Braun and Tcherniac, 1907). A cyclam (cyclic amine) was first synthesized by Alphen (1937). The preparation of the peraza-crowns was first developed by Stetter (1953a,... 

D. RING CLOSURE TO FORM A C—N—C LINKAGE FROM THE REACTION OF A PRIMARY AMINE OR AMIDE AND A DIHALIDE OR DITOSYLATE... 

The displacement of halogen from phosphonic dihalides with thiols in the presence of an appropriate base leads to 5,S-diesters rather than (9,5-isomers (equation 30 Z = 0)2-7374,375 gych a reaction has been employed in the determination of the enantiomer composition of chiral thiols. The NMR spectra for a series of phosphonodithioates 163 (Z = O, R = Me, Ph, PhCH2) and also for analogous trithiophosphonates 163 (Z = S, R = Me or Ph) in which the group R is derived from a chiral thiol, showed that the best separation of P NMR signals for the diastereoisomeric forms was achieved when R = Me. Displacement reactions which involve the loss of chlorine from R2P(Z)C1 (Z = or Se ). RP(0)(SR )CP and RP(S)(NHR )C1 by thiols in the presence of a tertiary amine base, and many more, are widely exemplified. 

Abstract. lonene polymers are polyammonium salts with positive nitrogens in the backbone, resulting from the polycondensation of diamines with dihalides or from the polycondensation of halo-amines. They combine with a variety of molecules of biological importance. The nature of binding and the resulting biological activity depends, to a considerable extent, on the structure and charge density of the polymer. 

Ionenes, also known as polyionenes, are polyelectrolytes with positively charged nitrogen atoms located in the backbone of polymeric chains. This type of polycation was first prepared by Gibbs et al [1], from dimethylamino-n-alkyl halides. The generic name of ionenes was suggested for these salts since the reaction of diamines with dihalides to form polyammonium salts proceeds through ionization of amines [2]. Kern and Brenneisen [3] reported that ionenes are formed by the Menshutkin... 

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