1,3-Dipolar cycloadditions of diazoalkanes to some nitrogen containing heteroaromatic systems

1,3‐Dipolar cycloadditions of (4R*,5R*)‐1‐alkylidene‐4‐(benzoylamino)‐5‐phenyl‐3‐pyrazolidinon‐1‐azomethine imines

“…The (1R*,2R*)-configuration of compounds 14a and the (1S*,2R*)-configuration of 15a were established on the basis of n.O.e. between H-C (5) and Me a -C(3) and n.O.e. between Me b -C(3) and H-C (2).…”

“…Asymmetric cycloadditions in chiral nitrone, nitrile oxide, and azomethine ylide series are well elaborated, however, much less examples have been reported in chiral azomethine imine series [1][2][3][4]. Stable chiral azomethine imines have been prepared from pyridazine-diazoalkane cycloadducts [5][6][7][8][9], 3-pyrazolidinones [10][11][12][13][14][15][16][17][18][19][20][21][22], and 1,3,4oxadiazin-2-ones [23][24][25][26]. Generally, 1,3-dipolar cycloadditions of such cyclic chiral azomethine imines to various dipolarophiles were accompanied by high facial and endo/exo-selectivity and afforded the corresponding functionalized fused pyrazolones with a bridgehead N-N structural element .…”

Construction of Bicyclic Ring Systems via a Transannular SmI2-Mediated Ketone−Olefin Cyclization Strategy

“…( Figure 1). [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In addition to these strategies, a third possible approach is the formation of bicycles via transannular cyclizations ( Figure 2).…”

Selective Synthesis and Cycloaddition Reactions of New Azomethine Imines Containing a 1,2,4‐Triazine Ring

“…For example, tetrahydropyrazolone derivative 1 gave the azomethine imine derivative 2 (Scheme 1). [1] Similar related transformations have also been carried out and a review [11] of this type of transformation has been published. More recently [12] analogous transformations of saturated pyridazines [13,14] and oxadiazinones [15,16] have also been reported.…”