Chemoselectivity in the isonitrile metathesis route to aromatic amines

Mechanism of the Generation of Ketenimine−M(CO)n Complexes (M = Cr, W, Fe) from Fischer Carbenes and Isocyanides

“…One of the key reactions of this class of compounds is the reaction of chromium(0) dienyl−ketenimine complexes 6 to produce o -alkoxyanilines 7 via a 6π electrocyclization process (Scheme ) . This reaction has been successfully applied to the preparation of analogues of indolocarbazole natural products, to the total synthesis of calphostins, and more recently to the synthesis of highly functionalized indazoles 12a and o -quinodimethide precusors 12b…”

Ruthenium-Catalyzed Cyclizations of Dienylalkynes Via Vinylidene Intermediates

“…In conclusion, we have presented the first examples of 6π-electrocyclization reactions involving vinylidene intermediates, readily generated from terminal acetylenes. We found that vinylidene intermediates are much less reactive than ketenes, but have about the same reactivity as ketenimines. ,, The ruthenium-catalyzed cyclization presented herein may be applicable to the synthesis of biologically relevant molecules containing complex aromatic structures. Further studies are in progress.…”

Photoinduced Reactions of Metal Carbenes in Organic Synthesis

“…23) [97]. The thermal insertion of isonitriles into these same classes of carbenes provided a complementary approach to similar benzannulations [98][99][100]. Manganese alkoxycarbene complexes underwent both inter- [101] and intramolecular [102] photodriven benzannulation reactions with alkynes (Eqs.…”