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O,O′‐decanoyl chitosan and O,O′‐decanoyl N,N‐didecanoyl chitosan, the lipophilic chitosans, as well as O,O′‐decanoyl chitin, the lipophilic chitin, were prepared from chitosan and chitin, respectively. All of these were soluble in chloroform, and the lipophilic chitosans were also soluble in toluene while O,O′‐decanoyl N,N‐didecanoyl chitosan was soluble also in hexane and kerosene. Solvent extraction of some selected metals, Cu(II), Ni(II), Co(II), Zn(II), Fe(III) and Pb(II), were tested using these lipophilic polysaccharides in chloroform. For extraction with O,O′‐decanoyl N,N‐didecanoyl chitosan, tests were also carried out using kerosene as the diluent. With O,O′‐decanoyl chitin, none of the metals tested were appreciably extracted. With O,O′‐decanoyl chitosan, copper(II) was highly selectively extracted over the other metals, while iron(III) was not appreciably extracted. On the other hand, iron(III) and copper(II) were selectively extracted over the other metals with O,O′‐decanoyl N,N‐didec...

Conjugate addition reactions of aldoximes to 3-crotonoyl-2-oxazolidinone and to 1-crotonoyl-3-phenyl-2-imidazolidinone are accelerated in the presence of a catalytic amount of Lewis acids. Among the chiral metal complexes with DBFOX/Ph, BOX/Bu- t , BOX/Ph, BOX/ o -OHBn, Pybox, or TADDOL ligands, the most effective thus far is the aqua complex derived from R , R -DBFOX/Ph and zinc(II) perchlorate. The reaction of 2-furancarbaldehyde oxime in dichloromethane in the presence of the R , R -DBFOX/Ph aqua complex derived from zinc(II) perchlorate hexahydrate (10 mol%) gave a moderate enantioselectivity of 64% ee at 0°C. Reactions using other metal complexes are also discussed.

In the presence of Lewis acid catalysts, aldoximes react with α,β-unsaturated carbonyl compounds at room temperature to give N-alkylnitrones in good yields. Combination of two Lewis acid catalysts, zinc(II) iodide/boron trifluoride etherate (50 mol%/50 mol%), is the best choice to mediate the reactions producing N-alkylated nitrones in excellent yields. In this procedure, a variety of aldoximes and α,β-unsaturated carbonyl acceptors can be employed.

In the presence of Lewis acid catalysts, aldoximes react with α,β-unsaturated carbonyl compounds at room temperature to give N-alkylnitrones in good yields. Combination of two Lewis acid catalysts, zinc(II) iodide/boron trifluoride etherate (50 mol%/50 mol%), is the best choice to mediate the reactions producing N-alkylated nitrones in excellent yields. In this procedure, a variety of aldoximes and α,β-unsaturated carbonyl acceptors can be employed.

Conjugate addition reactions of aldoximes to 3-crotonoyl-2-oxazolidinone and to 1-crotonoyl-3-phenyl-2-imidazolidinone are accelerated in the presence of a catalytic amount of Lewis acids. Among the chiral metal complexes with DBFOX/Ph, BOX/Bu- t , BOX/Ph, BOX/ o -OHBn, Pybox, or TADDOL ligands, the most effective thus far is the aqua complex derived from R , R -DBFOX/Ph and zinc(II) perchlorate. The reaction of 2-furancarbaldehyde oxime in dichloromethane in the presence of the R , R -DBFOX/Ph aqua complex derived from zinc(II) perchlorate hexahydrate (10 mol%) gave a moderate enantioselectivity of 64% ee at 0°C. Reactions using other metal complexes are also discussed.