Recently, the associate professor Fu Jiya and Professor Yuan Jinfang of College of Chemistry and Chemical Engineering published their important discovery in the fields of rapid construction of fluorene and its derivatives under metal-free catalytic conditions in the international academic journal <<Chemical Communications>> (IF=6.164). The paper was titled “Metal-free [3 + 3] benzannulation of 1-indanylidene-malononitrile with Morita–Baylis–Hillman carbonates: direct access to functionalized fluorene and fluorenone derivatives”.

Fluorenes as the privileged structural units, are ubiquitous in materials science due to their unique electrical and optical properties.  It has recently become one of the important synthetic subjects to develop efficient strategies for the construction functionalized fluorene derivatives. Fu Jiya and Yuan Jinfang's group first realized [3 + 3] benzannulation of 1-indanylidene-malononitrile with Morita–Baylis–Hillman carbonates for the selective formation of fluorene or fluorenone derivatives under the mild conditions. Meanwhile, 9-fluorenone derivatives with multifunctional groups can be obtained by adjusting the reaction conditions. Moreover, control experiment experiments, intermediate capture and quantum chemical calculations were performed to study the mechanism of the transformation process. This work enriched the structure types of fluorene compounds and provided a new methodology for the synthesis of fluorene compounds.

The first author of this paper is Xie Yasa,who is the 2016 graduate student of College of Chemistry and Chemical Engineering. The first corresponding author is Associate Professor Fu Jiya, and the first signature unit is Henan University. The quantum chemical calculations were supported by the team of Professor Zhao Lili of Nanjing Tech University.

This research supported by the College of Chemistry and Chemical Engineering, Henan Engineering Laboratory of Flame-Retardant and Functional Materials and Institute of Functional Organic Molecular and Engineering.

Link of the paper：https://doi.org/10.1039/D0CC00143K