2-(Tributylstannyl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-indole: Synthesis and use as a 1H-indol-2-yl-anion equivalent
作者:Giovanni Palmisano、Marco Santagostino
DOI:10.1002/hlca.19930760622
日期:1993.9.22
Pd-Catalyzed reaction of 2-(tributylstannyl)-1-[2-(trimethylsilyl)ethoxy]methyl}-1H-indole (5) with a variety of aryl, heteroaryl, vinyl, and allyl halides provides an efficient entry to the corresponding cross-coupled products (see Table).
Cyclodimerization of methyl 3-(indol-2-yl)propiolate 1 and 2-(indol-2-yl)-1-(phenylsulfonyl)acetylene 2 proceeds through an enyneâalkyne cycloaddition to give 4-(indol-2-yl)carbazoles.
Methyl indol-2-ylpropiolate 1 is synthesized by using a catalyst system of PPh3–CuI in the presence of K2CO3 as base. The procedure appears convenient if compared with Pd-catalyzed cross-coupling reactions. The interest is increased by the use of an alk-1-yne containing an electron-withdrawing group.
We report the first total synthesis and reassignment of the relative stereochemistry of naturally occurring 16-hydroxy-16,22-dihydroapparicine. Our novel route proceeds by a cascade reaction to efficiently construct a 1-azabicyclo[4.2.2]decane core, along with two stereocenters (C-15 and C-16). The C-16 quaternary carbon was constructed through stereospecific 1,2-addition using an indole nucleophile
The synthesis of 5-(indol-2'-yl)pyridin-2-ones and 5-(indol-2'-yl)pyran-2-one by Pd-catalyzed reactions is described. The best results are obtained using 2-indolylstannanes or 2-indolylzinc halides to be coupled with 5-bromopyridin-2-ones or 5-bromopyran-2-one in the presence of Pd(PPh3)(4) catalyst. Other Pd-catalyzed reactions are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.