A convenient synthesis of heterocyclic compounds containing 11-oxo-6,11,12,13-tetrahydrodibenzo[b,g][1,5]oxazonine fragment

Stefano Marcaccini: a pioneer in isocyanide chemistry

Stefano Marcaccini was one of the pioneers in the use of isocyanide-based multicomponent reactions in organic synthesis. Throughout his career at the University of Florence he explored many different faces of isocyanide chemistry, especially those geared towards the synthesis of biologically relevant heterocycles. His work inspired many researchers who contributed to other important developments in the field of multicomponent reactions and created a school of synthetic chemists that continues today. In this manuscript we intend to review the articles on isocyanide multicomponent reactions published by Dr. Marcaccini and analyse their influence on the following works by other researchers. With this, we hope to highlight the immense contribution of Stefano Marcaccini to the development of isocyanide chemistry and modern organic synthesis as well as the influence of his research on future generations. We believe that this review will not only be a well-deserved tribute to the figure of Stefano Marcaccini, but will also serve as a useful inspiration for chemists working in this field.

Synthesis and X-ray structural studies of a substituted 2,3,4,5-tetrahydro-1H-3-benzazonine and a 1,2,3,5-tetrahydro-4,3-benzoxazonine

Using a common 1-(1-phenylethenyl)-1,2,3,4-tetrahydroisoquinoline precursor to the required ylide or N-oxide intermediate, the Stevens [2,3] and analogous Meisenheimer [2,3] sigmatropic rearrangements have been applied to afford concise syntheses of phenyl -substituted representatives of each of the reduced 1H-3-benzazonine and 4,3-benzoxazonine systems, respectively. Single crystal X-ray structure determinations were employed to define the conformational characteristics for each ring type.

Annulation of Eight- to Ten-Membered Oxaza Rings to the Benzo[b]thiophene System by Intramolecular Nucleophilic Displacement

Concise synthetic routes to 2H-benzo[b]thieno[3,2-b][1,5]oxazocin-6(3H)-one, and the new benzo[b]thieno[3,2-b][1,5]oxazonin-7(2H)-one and 2H-benzo[b]thieno[3,2-b][1,5]oxazecin-8(3H)-one systems, have been developed based on intramolecular nucleophilic displacement in the key ring forming step.

2-(2-{2-[2-(Dibromo-meth-yl)phen-oxy]eth-oxy}benz-yloxy)benzaldehyde

The mol­ecule of the title compound, C₂₃H₂₀Br₂O₄, adopts a Z conformation as a result of inter­molecular C—H⋯Br bonding. One benzene ring, with the structure R-CHBr₂, makes a dihedral angle of 63.0 (2)° with the other benzene ring attached to the aldehyde group. Inter­molecular π–π stacking inter­actions [centroid–centroid distance = 3.698 (4) Å] and a weak C—H⋯Br contact is present in the crystal structure.