Rationally designed, chiral Lewis acid for the asymmetric induction of some Diels-Alder reactions

Nigrosporins A and B, New Phytotoxic and Antibacterial Metabolites Produced by a FungusNigrospora oryzae

“…The lH-NMR spectrum in DMSO-d 6 showed a methyl singlet at (5 1.21, and AB doublet at 62.60 and 2.84 (J = 18.0 Hz), and an ABX system at 3.63 (J = 5.3, 6.3 Hz) and 2.97 (2H, m). In adition to the lH-NMR data, cross peaks in HMBC spectrum of methyl 2-CH3 (6 1.21) to methylene C-1 (635.5), quaternary C-2 (669.2) and methine C-3 (670.7); methylene H-4 (62.97) to C-3 and C-2; methylene H-l (62.60,2.84) to C-3 corresponded to a partial structure i (Fig.…”

A study of chiral induction in some diene additions catalyzed by chiral alkoxyaluminum dichlorides

“…Kelly et al (9) obtained a remarkable ee (>98%) in diene additions to juglone (8-hydroxy-l,4-naphthoquinone), which had been made highly chiral by a bidentate attachment of a chiral borate. While this very elegant work with juglone (9) shows that high induction is achievable in diene additions to olefin bonds provided that a suitably bulky chiral catalyst is essentially jixed in a rigid conformation, the pioneering work using a chiral lanthanide (8) indicates that, in diene additions to a carbonyl group acting as dienophile, moderate chiral induction can be achieved without a rigidly held catalyst.…”

Crystal structure of pyridinium bis(naphthalane-2,3-diolato-κ2 O,O′)borate monohydrate, C25H20BNO5

“…To set an example, lithium salts of arylspiroboranate esters are being considered for their potential use as electrolytes in batteries [9]. Other applications of these particular type of compounds involve a use as catalysts, or co-catalysts, for the Diels-Alder reaction [10], methoxycarbonylation reactions [11], and in amide and ester condensation reactions [12]. As part of our ongoing study of the synthesis and structure of organoborate complexes [13][14][15][16], we have prepared a new organically templated borate using pyridine as the structure-directing agent.…”