Synthesis of substituted salicylamines and dihydro-2H-1,3-benzoxazines
摘要:
Phenols were converted to their magnesium salts with the MgCl2-Et3N base system and subsequently reacted with Eschenmoser's salt, affording N,N-dimethyl substituted benzylamines in high to excellent yields. A series of mono N-substituted benzylamines were prepared in one-pot syntheses by ortho-formylation of phenols to corresponding salicylaldehydes, which in turn reacted with amines to imines. The imines were subsequently reduced to mono N-substituted benzylamines. Some of these benzylamines were further converted, without work-up, to mono N-substituted dihydro-2H-1,3-benzoxazines. (c) 2007 Elsevier Ltd. All rights reserved.
2‐Amino‐4H‐chromenes were synthesized in moderate to good yields by the reaction of o‐quinone methides photochemically generatedfrom o‐(dimethylaminomethyl)phenols with malononitrile. This method was applicable to the synthesis of fluorinated chromenes that were difficult to obtain by other methods. In addition, o‐(hydroxymethyl)phenols could be used for the reaction in the presence of tertiary amine bases.
Studies in phenolic mannich bases - reaction with acetylenes
作者:K.K. Balasubramanian、S. Selvaraj
DOI:10.1016/s0040-4039(00)71523-1
日期:1980.1
3-Formyl, 3-benzoyl and 2,3-dibenzoyl-4H-Chromenes have been synthesised by the reaction of phenolic Mannichbases with electron-deficient acetylenic systems.
Oxidative ortho-amino-methylation of phenols via C–H and C–C bond cleavage
作者:Wenbo Sun、Huacan Lin、Wenyu Zhou、Zigang Li
DOI:10.1039/c3ra46373g
日期:——
Initiated by CCl3Br, phenols undergo efficient ortho-selective oxidative cross dehydrogenative coupling (CDC) with trimethylamine. When tetramethylethylenediamine (TMEDA) is used instead of trimethylamine, oxidative carbonâcarbon activation coupling (CAC) could occur to give the same salicylamines together with CDC by-products. These reactions are accelerated by a gold salt.