Regioselective Synthesis of 2- or 2,7-Functionalized Pyrenes via Migration

Efficient C(sp3)-P(V) bond cleavage and reconstruction of free α-aminophosphonates via palladium catalysis

Transition metal-catalyzed cleavage and reconstruction of the C-P bond provides a highly efficient and rapid method for the transformation of organophosphine compounds. In this study, a novel and general protocol for the palladium-catalyzed C(sp3)-P(V) bond cleavage of free α-aminophosphonates and subsequent functionalization via C-P bond recombination has been developed. The reaction exhibits high reactivity between the C(sp3)-P bond and halides, accommodating a wide range of substrates and enabling the rapid synthesis of aryl, alkenyl, and alkyl organophosphine molecules. Additionally, the synthetic utility is validated by gram-scale synthesis, and the reaction process is corroborated by mechanistic experiments.

Visible-Light-Induced Palladium-Catalyzed Construction of Polyarylfuran Skeletons via Cascade Aryl Radical Cyclization and C(sp3)-P(V) Bond Cleavage

Herein, a novel and expedient method was established for the synthesis of polyarylfuran derivatives. The coupling of allenylphosphine oxide and bromophenol or bromonaphthol enabled by visible light and palladium catalysis directly furnishes polyarylfuran skeletons, which involves a radical tandem cyclization and cascade C(sp³)-P(V) bond cleavage. This protocol features easy operation, a broad substrate scope, and a high step economy, affording polyarylfurans in moderate to good yields.

Synthesis of medium and large phostams, phostones, and phostines

Phostams, phostones, and phostines are a series of 1,2-azaphosphaheterocycle and 1,2-oxaphosphaheterocycle 2-oxide derivatives. They are phosphorus analogues of lactams and lactones and important biologically active compounds. The strategies for the synthesis of medium and large phostams, phostones, and phostines are summarized. They include cyclizations and annulations. Cyclizations achieve ring construction through the formations of C-C, C-O, P-C, and P-O bonds in the rings, while annulations build the rings via [5 + 2], [6 + 1], and [7 + 1] fashions with the stepwise formation of two ring bonds. This review includes the recent syntheses of seven to fourteen-membered phostam, phostone, and phostine derivatives.

Solvent-controlled regioselective arylation of indoles and mechanistic explorations

A new reaction for the regioselective arylation of indoles at C2 or C3 positions achieved by adjusting the solvent and with P(O)tBu2 as an auxiliary group is reported. And the experimental results and DFT confirmed the process.

Copper-catalyzed arylation of polycyclic aromatic hydrocarbons by the P[double bond, length as m-dash]O group

The first example of a directed and regioselective arylation of polycyclic aromatic hydrocarbons (PAHs) by using a P[double bond, length as m-dash]O directing group is reported herein. The protocol uses a cheap copper catalyst, and results in a breakthrough meta-selective C-H functionalization of arylphosphine oxide compounds. Substrates with potential fluorescence properties, for example, pyrene and fluoranthene, were successfully arylated under the system, thus achieving an efficient modification of fluorescent molecules containing the P[double bond, length as m-dash]O functional group.