Pentynol to furan conversion – Search for the best trans-[MX2(YNC10H14O)2] catalyst

Domino Sequences Involving Stereoselective Hydrazone-Type Heck Reaction and Denitrogenative [1,5]-Sigmatropic Rearrangement

Although the Heck reactions of alkene partners with various electrophiles have achieved great success, the variant focused on carbon═heteroatom counterparts still remains elusive. Herein, we report a Pd(0)-catalyzed asymmetric intramolecular hydrazone-type Heck reaction of N-[(Z)-3-iodoallyl]-aminoacetaldehyde and hydrazine hydrate (NH₂NH₂-H₂O), wherein the required hydrazone is in situ generated via an acid-promoted condensation. A key strategic advantage of this Heck paradigm is that the resultant Heck product allylic diazene rapidly undergoes stereospecific denitrogenative [1,5]-sigmatropic rearrangement, eventually furnishing a domino sequence toward 3-substituted tetrahydropyridine (THP) with high enantioselectivity. The substrate-induced diastereoselective version has also been realized, exclusively giving cis-2,5-disubstituted THPs. The utility of this sequence is demonstrated by the formal synthesis of multiple valuable bioactive targets, including 3-ethylindoloquinolizine, preclamol, and niraparib.

Oxygen activation by copper camphor complexes

In situreduction of CuCl₂enables formation of Cu(i) complexes prone to activate molecular oxygen from air towards catalytic oxidation of 1,3-dicarbonyls.

Selective hydration of ferrocenylethyne mediated by a palladium complex with a camphorhydrazone ligand

Complex [PdCl2L2], where L is a camphor hydrazone ligand, (1R,4S)-1,7,7-trimethyl-3-(2,2-dimethylhydrazone)-bicyclo[2.2.1]heptane-2,3-dione, efficiently promotes Markovnikov hydration of ethynylferrocene to acetylferrocene in aqueous methanol at room temperature. 1-Ferrocenylprop-1-yne and simple organic alkynes such as 1-octyne or ethynylbenzenes are not affected or polymerize under the reaction conditions.