Ruthenium catalyzed C-C bond formation via transfer hydrogenation: branch-selective reductive coupling of allenes to paraformaldehyde and higher aldehydes.
Under the conditions of ruthenium-catalyzed transfer hydrogenation employing 2-propanol as the terminal reductant, 1,1-disubstituted allenes 1a- h engage in reductive coupling to paraformaldehyde to furnish homoallylic alcohols 2a- h. Under identical transfer hydrogenation conditions, 1,1-disubstituted allenes engage in reductive coupling to aldehydes 3a- f to furnish homoallylic alcohols 4a- n. In all cases, reductive coupling occurs with branched regioselectivity to deliver homoallylic alcohols bearing all-carbon quaternary centers.
University of Texas at Austin, Department of Chemistry and Biochemistry, Austin, Texas 78712, USA.
Ming-Yu
MY
Ngai
Eduardas
E
Skucas
Michael J
MJ
Krische
D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D000466:Alkadienes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D006865:Hydrogenation; D015394:Molecular Structure; D010084:Oxidation-Reduction; D012428:Ruthenium / Q000737:chemistry*
D000438:Alcohols; D000447:Aldehydes; D000466:Alkadienes; C025947:propadiene; D002244:Carbon; D012428:Ruthenium