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An efficient synthesis of methylene-unsubstituted cyclopropane-fused indolines via photoredox catalyzed dearomative cyclopropanation of indole derivatives was developed.

Visible-light-induced cycloaddition reactions initiated via energy-transfer processes have recently evolved as powerful methods for the construction of strained cyclic molecules that are not easily accessed using known ground-state synthetic methods. Particularly, the reactions initiated by the excitation of aromatic rings provide an alternative solution to the direct transformations of aromatic feedstocks under the scheme of dearomatization. Vinylcyclopropanes (VCPs) are well-known reagents in radical clock experiments, working as a probe to detect transient radical intermediates. However, the synthetic applications in this regard still remain limited due to uncontrollable selectivities. Herein, we report visible-light-induced dearomatization of indole- or pyrrole-tethered VCPs, in which several competitive reaction pathways, including [5 + 2], [2 + 2], interrupted [5 + 2], and [5 + 4] cycloadditions, can be well regulated by engineering substrate structures and tuning reaction conditions. The reaction mechanism has been explored by combined experimental and computational investigations. These reactions provide a convenient method to synthesize structurally diverse polycyclic molecules with high efficiency and good selectivity.

Objective We present a prenatal case of 45,X/46,dic(X) with two asymmetric chromosome arms. Methods Single nucleotide polymorphism array(SNP-array),fluorescence in situ hybridization(FISH) and conventional cytogenetic analysis were performed for verification. Results The conventional G-banding analysis revealed a mosaic karyotype of mos 45,X/46,X,dic (X;X) (p11.2;q10) and the C-banding analysis showed that the derivative X chromosome had two darkly stained bands near the centromere.Two green signals and single green signal (X chromosome cetromere) were observed simultaneously in the metaphases and interphases FISH confirmation test,which indicated a mosaicism for X chromosome in the uncultured amniocytes.The SNP-array results revealed two copy-number-loss on the X chromosome.One was a 54.3Mb deletion in Xp22.33-p11.22 including 414 genes.Another was a mosaic deletion in Xp11.22-q28. Conclusion A combination of molecular and cytogenetic techniques should be employed to provide adequate genetic counseling to mosaic Turner sydrome patients for avoiding misdiagnosis.

A photocatalytic protocol for the divergent dearomative functionalization of indole derivatives is reported. Under the irradiation of visible light, either dimerization or reduction occurs selectively by modifying the reaction conditions, leading to the formation of the corresponding cyclobutane-fused polycycles and 2-substituted indolines in good yields with exclusive selectivity.

Expedient assembly of unprecedented molecular scaffolds from readily accessible starting materials in a sustainable fashion is highly pursued in modern organic chemistry. Herein, the first catalyti...