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The syntheses of several new simple negative, a simple positive, and multiple negative photochromes containing the dihydropyrene-cyclophanediene photochromic system are described. Electrochemical readout of the state of the switch is demonstrated for the benzo system as a potential useful alternative to optical readouts.

The opening of tartrate acetals with dialkylboron bromide is studied. The mechanism for the induction of diastereoselectivity that is derived from the opening is downstream for the ring fission.

Use of Pd/P(t-Bu)(sub 3) as a versatile catalyst for Stille reactions is discussed. The method is user-friendly and provided general method for cross-couplings of aryl chlorides and for room-temperature couplings of aryl bromides.

Technetium trichloride is prepared by reaction of [Tc.sub.2][([O.sub.2]CC[H.sub.3]).sub.4][Cl.sub.2] with HCl(g). The calculations on Tc[X.sub.3] (X = Cl, Br) have confirmed the stability of Tc[Cl.sub.3] and have shown the existence of a polymorph of Tc[Br.sub.3] with the Re[Br.sub.3] structure.

A newly developed palladium-catalyzed carboamination method was used to demonstrate the total synthesis of the racemic natural product ([plusmn])-tylophorine. The application of developed carboamination protocol as a key step to construct a natural product provides further evidence for its application in other products.

The room temperature Pd/P[(t-Bu).sub.3]-catalyzed cross-coupling of aryl bromides with alkynes promoted by substoichiometric amounts of Zn[Cl.sub.2] is reported. Pd(I) dimer is found to be a particularly active precatalyst for the general reaction which could be used for a wide variety of aryl bromides.

The application of the (2-pyridyl)acetone as a ligand for the copper-catalyzed reactions of phenols with aryl iodides, bromides and chlorides is discussed. The reaction is shown to exhibit excellent reactive selectivity, as well as functional group compatibility.

The development of a copper-catalyzed methodology for the coupling of vinyl bromides with azoles is described. The reaction is found to proceeds with various azoles and vinyl bromides and the double bond geometry of vinyl bromides is retained under the reaction conditions.

An efficient and reusable catalyst with PdEDTA immobilized in an ionic liquid brush and a green procedure was developed for coupling aryl iodides and bromides with phenylboronic acid. The reactions conducted in water under aerobic conditions with water-insoluble or even solid aryl halides gave excellent product yields and showed good environmental friendliness and catalyst recyclability.

A four-step synthesis method is described for cis-3,5-disubstituted morpholines from enantiomerically pure amino alcohols, where the key step is a Pd-catalyzed carboamination reaction between ethanolamine derivative and an aryl or alkenyl bromide. The morpholine products are generated as single stereoisomers and this method has provided access to fused bicyclic morpholines as well as 2,3- and 2,5-disubstituted products.

A highly efficient Cu-catalyzed C-O bond-forming reaction of alcohol and aryl bromides is developed. The transformation is realized by using copper(I) iodide as a catalyst, 8-hydroxyquinoline as a ligand, and [K.sub.3]P[O.sub.4] as a base.

A mild, racemization-free, palladium-catalyzed [alpha]-arylation of tetramic acids (2,4-pyrrolidinediones) is developed. The electron density of the aryl electrophile does not have any effect on their reactivity, both electron-rich and electron-poor aryl chlorides and bromides or triflates have led to good yields.

N-substituted thienodiazepinedione opening with a series of organomagnesium bromides has allowed the subsequent cyclization to the seven-membered ring thieno[3,2-e][1,4]diazepinone or to the six-membered ring thieno[3,2-b]pyridinones. The effective syntheses introducing considerable diversity onto these scaffolds are described.

The scope of Pd-catalyzed synthesis of N-Boc-protected anilines from aryl bromides and tert-butyl carbamate is described. This process is conducted at room temperature by using a combination of [Pd.sub.2][dba.sub.3].CH[Cl.sub.3] and a monodentate ligand, tert-butyl X-Phos.

A facile route is described for obtaining ynamides in high yields. The products are achieved through the iron-catalyzed C-N coupling reaction of amides with alkynyl bromides in the presence of 20 mol% of N,N'-dimethylethane-1,2-diamine (DMEDA).

CuI/4-hydroxy-L-proline-catalyzed coupling of aryl bromides and N-Boc hydrazine has taken place in DMSO to produce N-aryl hydrazides. These processes have allowed assembly of N-aryl hydrazides and primary arylamines that bear a wide range of functional groups including hydroxyl, amine, trifluoromethyl, ester, nitro and ketone.

A wide range of diaryl ethers and alkyl aryl ethers are prepared through intermolecular C (aryl)-O bond formation from the corresponding aryl iodides/aryl bromides and phenols/alcohols through Ullmann-type coupling reaction in the presence of a catalytic amount of ([plusmn])-diol L3-CuI complex under very mild reaction conditions. The catalytic system is not only capable of coupling hindered substrate but has also tolerated a broad range of a series of functional groups.

Parallel microscale experimentation is used for developing general conditions for the Suzuki-Miyaura cross-coupling of diversely functionalized primary alkyltrifluoroborates with a variety of aryl chlorides. The conditions obtained are amenable to coupling with aryl bromides, iodides and triflates.

The addition of elemental bromide dissolved in C[H.sub.2][Cl.sub.2] to para-disubstituted benzodiaocines, where X is the same (H, C[H.sub.3], Br, OMe, N[O.sub.2]) or a different substituent as X and Y (C[H.sub.3], Br; OMe, N[O.sub.2]) has proceeded with competition between two pathways. The regio- and stereoselectivities have established the capability of sulfonamide nitrogen centers to engage in neighboring group participation.

One mol % Pd loading of 4-hydroxyacetophenone oxime derived palladacycle or Pd[(OAc).sub.2] as precatalysts, [K.sub.2]C[O.sub.3] as base and water as additive was used to cross-couple potassium vinyl and alkenyltrifluoroborates with aryl and heteroaryl bromides to yield styrenes, stilbenoids, and alkneylbenzenes. These simple phosphine-free reaction conditions facilitate the palladium recycling from the aqueous phase during up to five runs by extractive separation of the products, which contain 58-105 ppm of Pd.

Molecular dynamics simulations are used for studying the structural transitions that accompany the encapsulation and dehydration processes. Solvated cetyl trimethylammonium bromide (CTAB) micelles have undergone a rapid inversion when transported to the gas phase and have formed very stable reverse micelles, independent of the amount of water present.

The reaction of monoesters of 1,2-allenyl phosphonic acids with Cu[X.sub.2] was used to develop a convenient and efficient method for the synthesis of 4-bromo- or 4-chloro-2,5-dihydro[1,2]-oxaphosphole 2-oxides in high yields. The Suzuki cross-coupling reaction of bromide and chloride products with organic boronic acids under the catalysis of Pd[Cl.sub.2][(Sphos).sub.2] resulted in 4-substituted-2,5-dihydro[1,2]oxaphosphole 2-oxides in moderate to good yields.

A study was conducted to determine the influence of cyclodextrins on the dimerization process of dibenzylimidazolium bromide in aqueous solution. The results obtained for the equilibria of 1,3-dibenzylimidazolium dimer might be applied to design other controllable self-aggregating systems.

A simple synthetic approach is described for the preparation and isolation of high-impurity bromide and chloride salts of some cyclic triphosphenium cations. The reactivity experiments on the undesired halogenated diphosphine byproducts have shown that the formation of brominated species can be prevented by increasing the concentration of cyclohexene used in the reaction.

The results from X-ray absorption fine structure (XAFS) study of aqueous dodecltrimethylammonium bromide (DTAB) and hexadecyltrimethylammonium bromide (HTAB) micelles are presented. The findings reveal at least two types of bromides on the cationic micelles, completely hydrated bromides and direct ion-associated with the micellar head groups.

The excision of chloride based Zr cluster units from solid-state start materials, their transformation to bromides by using EMIm-Br/Al[Br.sub.3] ionic liquids, the crystal structures of [(EMIm).sub.4][([Zr.sub.6]Z)[Br.sub.18]] (Z = Be, Fe) and spectroscopic data of the iron centered phase in different ionic liquids are reported. The results have concluded that this complete ligand exchange is considered as reversible, with the equilibrium being largely determined by the free ligand concentration.

The advances in catalytic asymmetric conjugate addition of Grignard reagents are presented and the scope of the technique is described. The mechanistic study of the catalytic process and the application of the catalytic system to the enantioselective [S.sub.N] 2' substitution reactions of allylic bromides with Grignard reagents are presented.

A concise synthesis of 11-O-debenzoyltashironin is developed. It is seen that the key transformation in the sequence involved a remarkable oxidative dearomatization/ transannular Diels-Alder cascade that allowed for the rapid assembly of the tetracyclic carbon skeleton of the natural product.

The structural and dynamical properties of the bromide ion in methanol are analyzed with Car-Parrinello molecular dynamics (CPMD) and are compared with those of [Cl.sup.-]. The differences in the coordination number with the chloride is attributed to the ionic radius and to the stronger perturbations brought by the solvent to the bromide ion.

A simple method is described for fabricating highly potent dual action antibacterial composites consisting of a cationic polymer matrix and embedded silver bromide nanoparticles. The ability to tune the release of biocidal [Ag.sup.+] ions from the composites is shown by controlling the size of the embedded AgBr nanoparticles and these composites are useful as antimicrobial coatings in a wide variety of biomedical and general use applications.

Suzuki-Miyura cross-coupling reactions carried out between potassium aryl- and heteroaryltrifluoroborates and alkenyl bromides are described. The process can be efficiently carried out using palladium catalyst with less than or equal to 2 mol % and 3 equiv of base in toluene/[H.sub.2]O.

A simple route for preparing single-crystal Ce(OH)[Co.sub.3] triangular microplates in the presence of the surfactant cetyltrimethylammonium bromide (CTAB) by hydrothermal treatment is demonstrated. Surfactant CTAB plays an important role in the growth of uniform Ce(OH)[Co.sub.3] triangular microplates.

The intramolecular cyclization of alpha-tributylstannyl radical with formyl group proceeds successfully for five-membered ring formation and the intermediate beta-tributylstannyl alkoxy radical undergoes a facile 1,3-stannyl shift and generates a beta-tributylstannyloxy-substituted carbon radical. The rearrangement is most likely irreversible and serves as a driving force to promote the cyclizations and hence beta-stannyloxy radicals can be used in further cyclizations to obtain tandem cyclization products.

A simple solution route is developed to hydrogen terminated silicon nanoparticles. Macroscopic amounts of powder can be obtained of either crystalline or amorphous nanoparticles, depending upon solvent and reaction conditions like temperature less than 300 degree Celsius.

A copper-catalyzed domino halogen exchange-cyanation procedure for aryl bromides is developed. The new method represents a significant improvement over the traditional Rosenmund-von Braun reaction, the reaction conditions are much milder, and the use of stoichiometric amounts of copper (I) cyanide and polar solvents is avoided, therefore, the isolation and purification of the nitrile products is greatly simplified.