Chain-extension reactions of aeetylenes. Part 4. Reaction of 1,3-dilithioacetylides with carbonyl electrophiles, hexamethylphosphoric triamide, and benzylideneaniline
作者:Keith A. Pover、Feodor Scheinmann
DOI:10.1039/p19800002338
日期:——
The regioselectivity of the reactions of 1,3-dilithioalk-1-ynes with various electrophiles has been examined. With formaldehyde and cyclic ketones, reactions occur both at C-1 and C-3 to give alk-2-yne-1,5-diols. In contrast reactions with carbon dioxide give allene-1,3-dicarboxylicacids.
Relay rhodium(I)/Brønsted acid catalysis for tandem arylation−cyclization reaction was developed. Chemodivergent syntheses of benzo-2H-pyrans and benzofurans from propargyl alcohols and ortho-hydroxylated arylboronic acids were achieved under this relay catalysis system. An ortho-hydroxy effect on changing the chemoselectivity and reactivity was observed.