Synthesis of a 2D Lander

Abstract

A method for the preparation of an asymmetric superbenzene is presented. The synthesis proceeds through the 12-fold cyclodehydrogenation of a polyaromatic precursor obtained by successive Diels-Alder additions of cyclopentadienones and alkynes.

Synthesis of Pyridylphosphonates by Rhodium‐Catalyzed [2+2+2] Cycloaddition of 1,6‐ and 1,7‐Diynes with Diethyl Phosphorocyanidate

“…Starting diynes 1a ,19 1b ,19 1c ,20 1d ,18 1e ,19 1f ,21 1g ,19 1h ,19 1i ,19 1j ,22 1k ,21 1l ,22 1m ,23 1n ,24,25 1o ,26 1p ,27 and 1q 22 were prepared according to the literature.…”

Mono‐ and Polyazatriphenylene‐Based Ligands: An Updated Library of Synthetic Strategies (2001–2018)

“…The reactions of the diyne 249 with various nitriles containing methyl, ethyl, vinyl, phenyl, hydroxyl, and carboxy groups proceeded in moderate to quantitative yields when conducted with 10 mol‐% of CpCo(CO) 2 catalyst in toluene under microwave irradiation for 10–20 min affording the desired azatriphenylenes 251 . The precursor diyne 249 was synthesized according to the previously reported method starting from (2′‐hydroxymethylbiphenyl‐2‐yl)methanol . This new azatriphenylene synthesis enabled the efficient assembly of the penta‐cyclic phenanthroindolizidine alkaloids dehydrotylophorine ( 1 ) and tylophorine ( 2 ).…”

“…The synthesis was commenced with the commercially available iodobenzene 252 which is selectively dimerized by the treatment with phenyliodine bis(trifluoroacetate) (PIFA) to give 253 in 84 % yield. A three‐step conversion via a Corey–Fuchs reaction was employed for the transformation of 253 into 255 . After synthesizing the diyne ( 255 ), it was treated with a cyano mesylate ( 256 ) to perform microwave‐mediated [2+2+2] cyclotrimerization reaction under cobalt catalysis in 20 min (Scheme ).…”

“…The reaction of the terminal diyne 257 and acetonitrile ( 250 ) proceeded at room temperature in the presence of the cationic rhodium(I)/BINAP complex (5 mol‐%) to give the corresponding azatriphenylenes 258 in good yields (Scheme ). The starting compound 257 was synthesized according to the previously reported method as described in Scheme …”

Palladium‐Catalyzed Regioselective Synthesis of 3‐(Hetero)Arylpropynamides from gem‐Dibromoalkenes and Isocyanides

“…[5] Applications of these building block molecules have been extended to the generation of acetylene derivatives, including alkynylphosphonates, [6] ynol ethers, [7] symmetric and asymmetric 1,3-diynes, [8] ynamides, [9] 1,2-diarylacetylenes, [10] ynoate esters, [11] and ynsilanes. [12] Piguel et al proposed a method for copper-catalyzed, C 2 -directed alkynylation of 3H-imidazo [4,5-b]pyridine derivatives using 1,1-dibromo-1-alkenes. [13] Bach et al reported the synthesis of propynamides by utilizing gem-dibromoalkenes and isocyanate under harsh, multi-step condi-tions, [14] whereas Xu et al established a process for the selective synthesis of 1,2-heterodisubstituted alkenes via nucleophilic b-addition to gem-dibromoalkenes followed by a cross-coupling reaction.…”