P(III)‐Mediated Cascade C‐N/C‐S Bond Formation: A Protocol towards the Synthesis of N,S‐Heterocycles and Spiro Compounds

Abstract

A P(III)‐mediated entry towards construction of C−N/C−S bond has been devised. The developed heterocyclization method was exercised for the synthesis of a diverse range of N,S‐heterocycles and related spiro molecules. P(NMe2)3 revealed the maximum efficacies under the aerobic reaction conditions and a spectrum of bis‐nucleophiles, and isothiocyanates were tolerated well to serve the access of manifold immense molecules.

New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

“…The rearrangement of 2-isothiocyano triarylmethanes in the presence of AlCl 3 were also used for the synthesis 2,4-diaryl-4 H -3,1-benzothiazines through aromatic ring transfer [ 20 ]. A facile protocol towards the synthesis of 4 H -3,1-benzothiazines was established by using a P(NMe 2 ) 3 -mediated C–N/C–S bond formation reaction of 2-aminobenzyl alcohol with isothiocyanates under aerobic conditions [ 21 ]. Despite of the above achievements, the development of new efficient methods for the synthesis of polysubstituted 3,4-dihydroquinazolines and 4 H -3,1-benzothiazines under mild reaction conditions is still of high demand in the discovery of biologically active compounds.…”

Cu-Catalyzed Three-Component Cascade Synthesis of 1,3-Benzothiazines from ortho-Aminohydrazones and Bromodifluoroacetamides

“…It exhibits unique pharmacological properties such as anti-inflammatory, analgesic, and anticancer properties (Scheme A) . As a consequence, a series of protocols for constructing benzo­[ d ]­[1,3]­thiazine motifs have been established (Scheme B) . For instance, Dondoni has developed a synthetic route in which ketenimines undergo a 1,4-cycloaddition with thiobenzophenones to form a six-membered benzo­[ d ]­[1,3]­thiazine adduct (Scheme B, route 1) .…”