Rh-Catalyzed Synthesis of Helically Chiral and Ladder-Type Molecules via [2 + 2 + 2] and Formal [2 + 1 + 2 + 1] Cycloadditions Involving C−C Triple Bond Cleavage

Hierarchical Assembly of a Phthalhydrazide‐Functionalized Helicene

“…[7] Enantiopure (M)-1 and (P)-1 were isolated by recrystallization and enantiomeric separation by column chromatography on a chiral support. The trimeric disk formation of 1 was first observed by 1 H NMR spectroscopy ( Figure 1 and Figure S3 in the Supporting Information).…”

Synthesis of Single and Double Dibenzohelicenes by Rhodium‐Catalyzed Intramolecular [2+2+2] and [2+1+2+1] Cycloaddition

“…[9] Reductivee limination from C affords 3.T he effect of the ligandso nt he chemoselectivity ([2+ +2+ +2] vs. [2+ +1+ +2+ +1]) might be explained as follows. [9] Reductivee limination from C affords 3.T he effect of the ligandso nt he chemoselectivity ([2+ +2+ +2] vs. [2+ +1+ +2+ +1]) might be explained as follows.…”

“…[4a, h] As an example of ad ibenzo-fused double helicene, Narita, Müllen, and co-workers reported the design ands ynthesis of ad ouble dibenzo [7]helicene by the Scholl reaction, whichg ave am ixture of chiral and meso isomers. [9] Interestingly,n ot only the [2+ +2+ +2] cycloaddition but also the formal [2+ +1+ +2+ +1] cycloaddition involving the CÀCt riple-bondc leavage [10] proceeded to give achiral ladder-type compounds. [9] Interestingly,n ot only the [2+ +2+ +2] cycloaddition but also the formal [2+ +1+ +2+ +1] cycloaddition involving the CÀCt riple-bondc leavage [10] proceeded to give achiral ladder-type compounds.…”

Diastereomeric Atropisomers from a Chiral Diyne by Cobalt(I)‐Catalyzed Cyclotrimerization

“…was added by syringe. 13 -1-(2-methylnaphthalen-1-yl)-5,7,8,9,9a,10hexahydro-pyrrolo[1,2- The reaction mixture was warmed to room temp.…”

“…), together with THF (10 mL), were cooled to 0°C in a Schlenk flask, then a solution of 15 (0.066 mmol in 0.4 mL Et 2 O, concentration of the catalyst stock solution: 0.122 mmol mL -1 ) was added. Additionally, a small amount of starting material was recovered (17 mg, 20 % 13 1-(3-Methyl-5,7,8,9,9a,10-hexahydropyrrolo[1,2-b][2,6]naphthyridin-1-yl)naphthalen-2-yl trifluoromethanesulfonate [(S)-(aR)-22]: Diastereomer (S)-(aR)-21 (130 mg, 0.39 mmol) was secured in a Schlenk flask and dissolved in CH 2 Cl 2 (4.5 mL) and Et 3 N (0.54 mL, 3.9 mmol). and stirring was continued for an additional 15 h. TLC control showed complete conversion.…”