Progress in Carbonylative [2+2+1] Cycloaddition: Utilization of a Nitrile Group as the π Component

Abstract

Neue Tricks in alten Reaktionen: 2‐(1,2‐Propadienyl)phenylacetonitrile werden in Gegenwart katalytischer Mengen [{RhCl(CO)dppp}2] (dppp=1,3‐Bis(diphenylphosphanyl)propan) unter CO‐Atmosphäre in Benzo[f]oxyindole umgewandelt (siehe Schema). Diese Aza‐Pauson‐Khand‐Reaktion überführt aliphatische Substrate in Azabicyclo[3.3.0]octadienone.

Catalyst‐Dependent Divergent Synthesis of Pyrroles from 3‐Alkynyl Imine Derivatives: A Noncarbonylative and Carbonylative Approach

“…We first utilized cyclopropyl-tethered 3-alkynyl imine 1 a [15,16] as the substrate and carried out the reaction in the [16a, 17,18] was used as the catalyst, the noncarbonylative product 2 a was obtained in almost quantitative yield without formation of 3 a ( The substrate scope of the ruthenium(0)-catalyzed reaction was next evaluated. Changing the R 2 substituent from a simple alkyl group to a benzyl, PMB, or 2-phenylethyl group afforded the desired products in excellent yields ( Table 2, entries 1-7).…”

Catalyst‐Dependent Divergent Synthesis of Pyrroles from 3‐Alkynyl Imine Derivatives: A Noncarbonylative and Carbonylative Approach

“…We first utilized cyclopropyl-tethered 3-alkynyl imine 1 a [15,16] as the substrate and carried out the reaction in the presence of [{Rh(CO) 2 Cl} 2 ] in a CO atmosphere. Compounds 2 a and 3 a were obtained in 11 % and 81 % yields, respectively ( Table 1, entry 1; for details see Scheme S7 in the Supporting Information).…”

“…Compounds 2 a and 3 a were obtained in 11 % and 81 % yields, respectively ( Table 1, entry 1; for details see Scheme S7 in the Supporting Information). Next, we turned our attention to find the optimized reaction conditions for the current reaction by screening various rhodium catalysts such as the Wilkinson catalyst, [Rh 6 (CO) 16 17,18] was used as the catalyst, the noncarbonylative product 2 a was obtained in almost quantitative yield without formation of 3 a ( The substrate scope of the ruthenium(0)-catalyzed reaction was next evaluated. Changing the R 2 substituent from a simple alkyl group to a benzyl, PMB, or 2-phenylethyl group afforded the desired products in excellent yields ( Table 2, entries 1-7).…”