Synthesis of optically active oligonaphthalenes via second-order asymmetric transformation

Synthesis of numerous optically active rod-shaped oligo(2,3-dioxyfunctionalized)naphthalenes connected at their 1,4-positions was achieved using oxidative coupling under CuCl2/alpha-methylbenzylamine conditions by second-order asymmetric transformation. We believe this method is practical and should contribute to the field of material science.     

Unconditionally secure key distribution based on two nonorthogonal states

We prove the unconditional security of the Bennett 1992 protocol, by using a reduction to an entanglement distillation protocol initiated by a local filtering process. The bit errors and the phase errors are correlated after the filtering, and we can bound the amount of phase errors from the observed bit errors by an estimation method involving nonorthogonal measurements. The angle between the two states shows a trade-off between accuracy of the estimation and robustness to noises.     

Asymmetric alkylation of N-toluenesulfonylimines with dialkylzinc reagents catalyzed by copper-chiral amidophosphine

The synthetic procedure of a chiral amidophosphine ligand 5 bearing two bulky substituents, 2,4,6-trimethylphenylmethyl or 2,4,6-triisopropylphenylmethyl groups, on the pyrrolidine ring was improved by employing the borane-THF reduction of the lactam-alcohol intermediate 8. The resulting amino alcohol was selectively acylated to give an amide-alcohol 11, which was then converted to the chloride 12 in 55-73% yields by the treatment with methanesulfonyl chloride in collidine. The reaction of the chloride 12 with NaPPh(2) in dioxane-THF gave an amidophosphine 5 in an acceptably high 82-83% yields. Addition of a hexane solution of dialkylzinc reagent to a mixture of catalytic amount of an amidophosphine 5, copper species, and N-toluenesulfonylimine 1a of benzaldehyde in toluene provided a solution which gave the alkylated amide 3 in high yield and enantioselectivity up to 96%. A survey of copper sources and solvents concluded that copper(II) ditriflate and copper(I) triflate-benzene complex as good copper sources and toluene as a choice of solvent. N-Toluenesulfonylimines 1a-e of arylaldehydes, furfural, and alkanals were successfully ethylated with diethylzinc to give the corresponding N-toluenesulfonylamides 3aE-eE in satisfactorily good 69-97% yields and high 86-96% enantioselectivities.     

Limit theorems for one-dimensional diffusions and random walks in random environments

Summary The limiting behavior of one-dimensional diffusion process in an asymptotically self-similar random environment is investigated through the extension of Brox's method. Similar problems are then discussed for a random walk in a random environment with the aid of optional sampling from a diffusion model; an extension of the result of Sinai is given in the case of asymptotically self-similar random environments.