Reactions of phosphorus compounds. 37. Preparation of .beta.-iminopropyl- and .beta.-aminopropenyltriphenylphosphonium bromides and the use of the latter in heterocyclic synthesis

Synthetic studies using unsaturated and active phosphonium salts. A convenient preparation of furano‐ and pyrano[2,3‐c]pyridazines and substituted quinolines

“…Summarizing, although the initial step in all of the present (Schemes 6-8) and previous work (Scheme 2 in [2]) is nucleophilic attack by the carbanions at the azomethine portion in 2, the consequences of the initial step vary markedly according SCHEME 8 to the structure of the phosphoranes. It is worth mentioning here that the methods previously described for the preparation of substituted quinolines 23a [13] and 23b [14] are lengthy and indirect.…”

Synthesis of Substituted 2-Pyridyl-4-phenylquinolines

“…The literature describes numerous different ways to prepare substituted quinoline rings: i.e., by exploiting quinoline carboxamides [ 7 ], acid-catalyzed condensation of o -aminobenzophenones [ 8 ] with ketones [ 9 ], sequential vinylic substitution/annelation processes [ 10 ], reactions of N-arylnitrilium salts with acetylenes [ 11 ], cyclodehydration of o -vinyl anilides [ 12 ], intramolecular Wittig reactions [ 13 ], and cyclization of oximes [ 14 ]. Using o -isocyanostyrenes only symmetric biquinoline may be prepared [ 15 ].…”

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

“…The same authors carried out a series of nucleophilic additions of amines and hydrazine derivatives to 24 to obtain products with the proposed structure of 2-aminovinylphosphonium salts 27 in equilibrium with their tautomeric imine form 28 ( Scheme 18 ). Depending on the nature of the substituent R, the enamine or the imine form predominated ( Table 3 ) [ 33 ].…”

“…2.3.1. Deprotonated 2-aminovinylphosphonium salts in the Wittig reaction: 2-Aminovinylphosphonium salts, which are the addition products of amines to 2-propynylphosphonium bromide [ 33 ] or can be obtained by deacylation of 2-( N -acylamino)vinylphosphonium salts [ 34 – 35 ], have been found to have several interesting synthetic applications, although they have only relatively recently become known.…”