Novel asymmetric synthesis of spiroindene-1,3dione-pyrrolidines via CoII/amino acids complex catalysed asymmetric 1,3-dipolar cycloaddition of azomethine ylides and 2-arylidenindane-1,3-diones

Indane-1,3-Dione: From Synthetic Strategies to Applications

“…Then, the metallocycle could undergo a reductive elimination, giving the final product 310 and regenerating the catalyst 311 (see Scheme 79). Cobalt (II) was also used as a metal catalyst to initiate 1,3-dipolar cycloadditions between azomethine ylides 314 and 2-arylidene-indane-1,3-diones 255 [269]. This metal cation can be chelated with two phenylalanine units, forming a planar complex of cobalt (II).…”

“…The reaction tolerates all substituents examined, except that higher reaction yields were obtained while introducing electron withdrawing groups on the azomethine ylides 314. Cobalt (II) was also used as a metal catalyst to initiate 1,3-dipolar cycloadditions between azomethine ylides 314 and 2-arylidene-indane-1,3-diones 255 [269]. This metal cation can be chelated with two phenylalanine units, forming a planar complex of cobalt (II).…”

“…Reaction Mechanism supporting the formation of a unique diastereoisomer during the cycloaddition of azomethine ylides 314 and arylidene-indane-1,3-diones 255. Reproduced with permission from Ref [269]…”

Regio- and diastereoselective synthesis of diverse spirocyclic indenes by cyclization with indene-dienes as two carbon building blocks

“…[1][2][3][4][5] Therefore, the synthesis of these interesting scaffolds has attracted intensive attention from the chemistry community. And many elegant building blocks have been devised to achieve this goal, including 1-indanone and its derivatives, [6][7][8] 1,3-indanedione and its derivatives, 9,10 and others. [11][12][13][14][15][16][17][18][19] As sterling building blocks for the construction of polycyclic indene frameworks, indenedienes have aroused great interest of synthetic chemists due to their unique structural features in the synthesis of polycyclic indene scaffolds, 20 and they could serve not only as four-atom reaction partners in (4 + n) annulation for constructing indene-fused cyclic scaffolds, but also as two-atom reaction partners in (2 + n) annulation for constructing spiroindene scaffolds (Scheme 1b).…”

“…With the amount ratio of 1 : 2, a 79% isolated yield of 3a could be obtained (entry 8). Afterward, several representative solvents were evaluated (entries [9][10][11][12][13][14][15][16][17]. The results demonstrated that the solvents had an apparent influence on the yields and 1,2dichloroethane was the best choice for this (4 + 2) cyclization (entry 13).…”