A Tandem Elimination−Cyclization−Suzuki Approach: Efficient One-Pot Synthesis of Functionalized (Z)-3-(Arylmethylene)isoindolin-1-ones

Abstract

A novel and efficient one-pot regioselective elimination-cyclization-Suzuki approach was developed to afford (Z)-3-arylmethyleneisoindolin-1-ones in good to excellent yields from easily accessible o-gem-dihalovinylbenzamides and organoboron reagents.

Efficient one-step synthesis of chiral bidentate oxazoline-alcohol ligands via a cyclic imidate ester rearrangement

“…5a In order to verify if this chirality switch also holds for other ligands, we synthesized (1S,2R)-14 as an analogue of (1S,2R)-6aA with a CPh 2 -tether (Scheme 2). When the diethylzinc addition was performed in the presence of 14, indeed the opposite enantiomer (R)- (12) was obtained in 86% yield, but with only 22% ee.…”

Reaction of benzal bromides in water/dioxane system for easy access to benzaldehydes and 2-formylbenzonitriles (2-cyanobenzaldehydes)

“…Compounds 7a, 7d, 9b, 9e, 10 and 13a were prepared according to the literature. 5,33 Compounds 1a, 1c-e, 7a-d, 9f-g, 13a-d and 14a-d were identified comparing their spectral data with the literature reported. 5,7,[34][35][36][37][38][39][40] Spectroscopic data are given only for compounds never previously described.…”

“…2,[5][6][7][15][16][17] In addition, many of the existing synthetic methods suffer from certain limitations with respect to yield, reaction conditions and toxicity. In particular, the formylations of 6, performed under strongly basic conditions, usually lead to 1 in rather low yields.…”

“…NaOH) at high temperatures, [25][26] conditions too harsh for the synthesis of 2-formylbenzonitriles, Therefore, the transformation of benzal halides 7 into 2-formylbenzonitriles have been reported under milder conditions only in the presence of the rather expensive AgNO3, used in large excess (> 3 eq. ), [5][6][7] with severe limitations concerning the scale of the synthetic procedure, the necessity of additional tedious purification operations and eventual metal contamination. In our ongoing project on large-scale reaction of 2-formylbenzonitriles, we came across these problems and we realized that not much attention has been devoted to the development of simple and effective methods for the synthesis of these valuable aldehydes.…”

“…The obtained results are, however, comparable with those reported in literature for the hydrolysis performed in the presence of AgNO3. [5][6][7] In addition, the methodology herein described allows the access to several new 2-formylbenzonitriles (products 1b,c,f-i). Only the benzal bromides bearing the 5-NO2 and 4-NO2 substituents (7b and 7i) were less reactive, giving the respective aldehydes in rather low yields (Entry 4 and 11).…”