Palladium-catalyzed coupling of 2-bromoanilines with vinylstannanes. A regiocontrolled synthesis of substituted indoles

Abstract

c 2.1, H20) (lit.3 [a]22D -86.9°(c 2.1, H20)).

New 2,2'‐Substituted 6,6'‐Dimethylbiphenyl Derivatives Inducing Strong Helical Twisting Power in Liquid Crystals

“…The synthetic routes to the chiral dopants ( For (-)-(M)-7a and (-)-(M)-7b, Sandmeyer-type bromination [2] of 2-methyl-6-nitroaniline (93 % yield) was used as the first reaction step. This was followed by Ullmann coupling (86 % yield) and reduction of the nitro group to the corresponding diamine rac-4 under hydrogen (99 % yield), (Scheme 1).…”

The Palladium‐Catalyzed Synthesis of Aromatic Heterocycles

“…For example, Hegedus anilines can undergo palladium-catalyzed cyclization as a general route to indoles (Scheme 6.30) [40]. The formation of these 2-vinyl-N-tosyl-aniline substrates can also be accomplished via palladium catalysis, via a Stille coupling of 2-haloaniline derivatives with vinylstannanes, followed by subsequent conversion to the indole via oxidative cyclization [41].…”

Preparation and NMR Analysis of 2,6-Heterodifunctional Halobenzenes as Precursors for Substituted Biphenyls

“…15 Methyl 3-amino-2-bromobenzoate (13). 11 Ester 12 (3.00 g, 11.50 mmol) was dissolved in glacial acetic acid (15 mL) and the solution was heated to 120ЊC. Reduced iron powder (2.15 g, 38.60 mmol) was added in one portion and the mixture was stirred at 120ЊC for 2 h. The hot mixture was poured into water, the organic materials were extracted with methylene chloride, and the solution was passed through a silica gel plug to give 2.30 g (87% yield) of the product as a light yellow oil, which was used without additional purification: MS m/e (relative intensity) 231 ((Mϩ2) ϩ , 96), 229 (M ϩ , 92), 200 (88), 198 (100), 90(72).…”

“…2,6-Disubstituted halobenzenes (I) are relatively rare and constitute a class of important precursors to biologically active 1,2 and naturally occurring compounds, [3][4][5] intermediates for heterocycles, 1,[6][7][8][9][10][11] and building blocks for ortho-polysubstituted biphenyls. [12][13][14] Most of the known halobenzenes I contain carbon-, nitrogen-, and oxygenbased substituents X and Y.…”