Metal-Free C–C/C–N/C–C Bond Formation Cascade for the Synthesis of (Trifluoromethyl)sulfonylated Cyclopenta[b]indolines

Abstract

A bis(triflyl)ethylation [triflyl = (trifluoromethyl)sulfonyl] inserted into a sequential cyclization cascade resulted in the direct formation of gem -bis(triflyl)ated cyclopenta[ b ]indolines from anilide-derived allenols and alkenols. This catalyst- and irradiation-free sequence facilitated the efficient preparation of functionalized tricyclic indoline cores bearing two contiguous stereocenters. The formed cyclopenta[ b ]indolines can be easily transformed into a wide variety of triflylated indolines, including the tetracycle ring system found in polyveoline.

Hydroformylation of Alkynyl Sulfides: A Stereo‐ and Regioselective Route to α‐Sulfenyl Acroleins

“…Finally, for the sulfonylacrolein 7, heating at 125 °C for 24 hours allowed the stereospecific obtention of cycloadduct 10 as a single cis isomer, with 76% yield. [23] Thus, depending on the degree of oxidation of the sulfur atom, it is possible to selectively obtain the functionalized cyclohexene carbaldehyde in trans or in cis relative configuration, or the cyclohexadiene carbaldehyde.…”

Synthesis of Polycyclic Aromatic Hydrocarbons Decorated by Fluorinated Carbon Acids/Carbanions

“…These results imply that the PMP group on the alkyne terminus is not essential for the initial electrophilic addition of Tf 2 C=CH 2 , but it serves as a directing group to regulate the regioselectivity. In the cases of gem-diarylallenes 9, [23] the reaction with 1 gave indene sodium salts 10 through 5-endo-trig cyclization (Eq. ( 3)); for other examples, see the Supporting Information) after silica gel column chromatography.…”