The study on the key steps of carbonylations and double carbonylations results in finding five synthetically important catalytic reactions. i) Palladium catalyzed carbonylation of allyl phosphates, ii) palladium catalyzed carbonylation of allyl acetates, iii) rhodium catalyzed azacarbonylation of allyl phosphates, iv) palladium catalyzed carbonylation of allylamines, v) palladium catalyzed cross double carbonylation of amines and alcohols. Carbonylated products such as β, γ-unsaturated carboxylic acids, their esters and amides, and oxamates are versatile synthetic intermediates for organic synthesis. The mechanistic aspects of these reactions and synthetic applications are described.
Vicinally donor-acceptor-substituted 2, 2-dialkoxycylopropanecarboxylic esters 4 are equivalents of 1, 3-zwitterions and have been proved to be valuable synthetic building blocks in organic synthesis. We describe herein the Lewis acid-mediated highly diastereoselective reactions of 4 with (1) esters or acid chlorides to give Claisen-type addition products ; (2) carbonyl compounds to afford γ-lactones ; (3) N-tosylaldimines to give γ-lactams. We also describe the Lewis acid-mediated reactions of 4 with trimethylsilylketene and ketene silyl acetals, affording cyclopentenone derivatives.
Molecular nitrogen was incorporated into organic compounds via titanium nitrogen complex [TiNMg2Cl2·THF]. Namely, the reaction of titanium isocyanate complex [3THF· Mg2Cl2OTiNCO] prepared from titanium nitrogen complex [TiNMg2Cl2·THF] and CO2 with acid anhydrides afforded cyclic imides and quinazoline derivatives. Using the combination system of nitrogenation and palladium catalyzed carbonylation, phthalimide, isoindolinone, and quinazolines were synthesized from an aryl halide. Furthermore, coupling reaction of ketones with an aryl or vinyl halides in the presence of Pd (0) and titanium isocyanate complexes smoothly proceeded to give divinyl amines or arylvinyl amine via transmetalation.