Additions to trivalent functionalities

The sonochemical Barbier reaction was used advantageously in condensations 

Dodecanedial is obtained in 83% yield from 1,10-dibromodecane. In a patent, the 

The results can be improved by stabilizing the a-aminoalkoxide intermediate, and N,N -trimethyl-N formyl-ethylenediamine gives optimal yields. With this substrate, a frequency effect is observed in diethyl ether (Fig. 59). No reaction can be detected at 50 kHz, but the expected products form at 500 kHz in 30-45 min.3i4 

Reaction in THP at 50 kHz followed by lithiation of the intermediate a-amino-alkoxide on its ortho position and quenching with electrophiles provide ortho-substituted benzaldehydes in a one-step protocol. 

With isocyanates (Eq. 72) a Barbier reaction leading to aromatic amides from an aryl bromide is best done with sodium.  

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