Derivatives of Fluorene. X. Fluorofluorenes. III¹

The Ullmann Synthesis of Biaryls, 1945-1963

“…An exception to this generalization is the observation that extensive dehalogenation and a poor yield of biaryl was obtained from methyl l-bromo-2-naphthoate which had been purified by recrystallization, apparently due to the halide was purified by vacuum distillation, an 87% yield of biaryl was obtained (11). The Ullmann coupling of 3-fluoro-4-nitroiodobenzene with an equimolar mixture of methyl o-chloroand o-bromobenzoate gave a better yield of the unsymmetrical biaryl than either oh alo ester alone (93).…”

The synthesis of non‐symmetrical stilbene analogs of trans‐resveratrol using the same Pd catalyst in a sequential double‐Heck arylation of ethylene

“…Chemicals were purchased from commercial sources and were used without further purification. 1‐iodo‐3,5‐dinitrobenzene36 and 1‐bromo‐3,5‐dinitrobenzene37 were obtained using procedures that have been described in the literature. Elemental analyses were performed by the Analytical Central Service of IQ‐UFRGS.…”

Bi-Blatter diradicals: convenient access to regioisomers with tunable electronic and magnetic properties

“…13 C{ 1 H} NMR (CDCl 3 , 100 MHz) d 155.7 (d, 1 J FC = 267.7 Hz), 137.9, 134.9 (d, 3 J FC = 4.2 Hz), 133.9 (d, 2 J FC = 8.7 Hz), 124.7 (d, 3 J F-C = 2.5 Hz), 119.8 (d, 2 J F-C = 21.5 Hz). 19 3,3 0 -Difluoro-4,4 0 -dinitrobiphenyl (5 [7,7]) 95 . Following the general procedure, biphenyl 5 [7,7] (1.064 g, 3.800 mmol, 35% yield; 31-42% yield for several runs) was obtained from 2-fluoro-4-iodo-1-nitrobenzene 79 Preparation of N 0 ,N 0 0 0 -(dinitrobiphenyldiyl)bis(pivalohydrazides) 6[m,n]: a general procedure A solution of difluoro-dinitrobiphenyl 5[m,n] (1 mmol, 1 equiv.)…”