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Research has been conducted on nitrogenase cross-linked complex. The structural and biochemical characterization of this complex carried out to assess the mechanistic relevance of these species is described, and the results demonstrate that this chemical cross-link is formed by N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide reaction.

The first catalytic enantioselective allylic substitution reaction with alkylboron compounds has been achieved. The reaction between alkyl-9-BBN reagents and primary allylic chlorides proceeded with excellent γ-selectivities and high enantioselectivities under catalysis of a Cu(I)-DTBM-SEGPHOS system. The protocol produces terminal alkenes with an allylic stereogenic center branched with functionalized sp³-alkyl groups. The reaction with a γ-silicon-substituted allyl chloride affords an efficient strategy for the enantioselective synthesis of functionalized α-stereogenic chiral allylsilanes. [ABSTRACT FROM AUTHOR]

The first catalytic enantioselective conjugate addition of alkylboron compounds has been achieved. Reactions between alkylboranes and imidazol-2-yl α,β-unsaturated ketones proceeded with high enantioselectivity under the influence of a Cu(I) catalyst system, prepared in situ from CuCl, a new chiral imidazolium salt as a precursor for the N-heterocyclic carbene ligand, and PhOK. Alkylboranes are widely obtained via alkene hydroboration. A variety of functional groups are tolerated in alkylboranes and α,β-unsaturated ketones. [ABSTRACT FROM AUTHOR]

Conjugate addition of alkylboron compounds (alkyl-9-BBN) to imidazol-2-yl α,β-unsaturated ketones proceeded in the presence of a catalytic amount (10 mol %) of CuCl, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), and t-BuOK. The alkylboranes are available through alkene hydroboration, and thus the overall process represents a reductive conjugate addition of alkenes to enone derivatives. A variety of functional groups are tolerated in both the alkenes and the α,β-unsaturated ketones. The 2-acylimidazole moiety can easily be converted into the corresponding carboxylic acid, ester, and amide derivatives.