A Cu(OTf)₂-catalyzed cascade cyclization reaction of simple homopropargylic amines was developed. The sequence involved an intramolecular radical hydroamination cyclization followed by dimerization by a Povarov-type reaction. Through this cascade reaction, a complex nitrogen-containing tetracycle framework was constructed in one pot with the formation of four new bonds and five stereocenters. Noteworthy, the aglycon of the natural product incargranine B was facilely and efficiently synthesized by using this method.

A highly chemoselective, palladium-catalyzed, cascade coupling-cyclization of allenol derivatives containing multiple functional groups was developed. Through this reaction, a series of functional dihydrobenzofuranols or chromanols and indolinols was easily obtained in good to high yields.

An unexpected double Diels–Alder (DDA) reaction of (E)-2-bromo-4-aryl-1,3-pentadiene was developed and resulted in a series of “butterfly-like” bicyclo[2.2.2]octene derivatives in moderate to good yields without the need for a metal catalyst. The proposed mechanism involves a [1,5]-sigmatropic hydrogen migration and HBr elimination. Through this decisive [1,5]-hydrogen shift step, the electronic properties and steric hindrance of the conjugated diene substrate are completely altered and the DDA reaction of this potential diene synthon is successfully achieved.

Rhodium(I) carbenes were generated from propargylic alcohol derivatives as the result of a dehydrative indole annulation. Depending on the choice of the electron-withdrawing group on the aniline nitrogen nucleophile, either a cyclopropanation product or dimerization product was obtained chemoselectively. Intramolecular hydroamidation occurred for the same type of propargylic alcohol derivatives when other transition-metal catalysts were employed.

Rhodium(I) carbenes were generated from propargylic alcohol derivatives as the result of a dehydrative indole annulation. Depending on the choice of the electron-withdrawing group on the aniline nitrogen nucleophile, either a cyclopropanation product or dimerization product was obtained chemoselectively. Intramolecular hydroamidation occurred for the same type of propargylic alcohol derivatives when other transition-metal catalysts were employed.

An organophosphane catalyst derived from L-proline was shown to be a very effective catalyst for asymmetric Michael addition reactions of various chalcones to cyclic ketones including both cyclohexanone and cyclopentanone. The corresponding adducts could be obtained in high yields (up to 91 %) and with excellent enantioselectivities (up to 99 % ee) and diastereomeric ratios (up to >99:1). A possible catalytic mechanism, based on ³¹P NMR and ESI-MS observations, for this organophosphane-catalyzed Michael addition has been proposed.

Two kinds of immobilized palladium (Pd) catalysts were prepared by reversible addition fragmentation chain transfer polymerization of pyridine-containing monomer followed by immobilizing palladium chloride (PdCl₂) on block copolymers. Namely, one of them includes the cross-linking structure of maleic anhydride with 1,6-diaminohexane (cross-linker), polystyrene-block-poly(4-(4-vinylbenzyloxy)butylpicolinate-alt-maleic anhydride)-Pd (PS-b-P(VBP-alt-MAn)-Pd), and the other is its non-cross-linking counterpart, polystyrene-block-poly(4-(4-vinylbenzyloxy) butylpicolinate)-Pd (PS-b-PVBP-Pd). From transmission electron microscopy images, it could be observed that they both assembled into micelles in the selective solvents. The Pd of PS-b-P(VBP-alt-MAn)-Pd located in the core of micelles, whereas the Pd of PS-b-PVBP-Pd was on the shell of the micelles. The PS-b-P(VBP-alt-MAn)-Pd can be continuously used for five times without any appreciable loss of activity in the aqueous Suzuki-coupling reaction. However, the catalytic activities of the PS-b-PVBP-Pd decreased sharply with the increase in the recycle times. Thus, this promising cross-linking strategy not only greatly restrained the loss of Pd in the catalytic cycles, but also effectively maintained the immobilized Pd catalyst's high activity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A series of well-defined different chain lengths polymers, which contain the organometallic 1,3-dichloro-tetra-n-butyl-distannoxane core in the main chain, was obtained in one-pot via a novel 1,3-dichloro-tetra-n-butyl-distannoxane (complex A)/azobisisobutyronitrile (AIBN) initiating system used in reverse atom transfer radical polymerization of styrene in different concentrations. The introduction of organotin complex A was supported by ¹H-NMR, ¹³C–NMR, and the Inductive Coupled Plasma Emission Spectrometer analysis of the organotin-containing polymer. Moreover, the mechanism of polymerization was investigated by changing the ratio of complex A to AIBN. It was concluded that the complex A not only acted as an important part of the initiator system but also introduced the functional organometallic group into the polymer chain. Additionally, the organotin-containing polymer could be used as catalyst for esterification, and the reaction products' conversion could reach high up to 99% and does not decrease after four successive cycles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A series of new well-defined nanoparticles containing an organotin core and a polystyrene shell were obtained by crosslinking of n-Bu₂SnO with various chain-length amphiphilic polystyrene-b-poly-(6-(4-vinylphenoxy) hexanoic acid. The amphiphilic copolymers were synthesized via reversible addition fragmentation chain transfer polymerization and hydrolysis. The structures of the nanoparticles were studied by the transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy analysis. Notably, the morphology of the crosslinked copolymer showed individual nanoparticles with regularly spherical shape. And the nanoparticle diameters decreased with increasing number of organotin carboxylate units. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

1,3-Dichloro-tetra-n-butyl-distannoxane was firstly used to catalyze the direct substitution of 9H-xanthen-9-ol with indoles at room temperature to afford a class of 3-(9H-xanthen-9-yl)-1H-indole derivatives in good to excellent isolating yield. Moreover, other nucleophiles (such as diketone and pyrrole) could also proceed smoothly in this methodology. Copyright © 2012 John Wiley & Sons, Ltd.

L-Prolinethioamide derivative 1c, prepared from the readily available natural amino acids L-proline and L-valine, was studied for the direct asymmetric aldol reaction of acetone with various aromatic aldehydes at 0 °C or room temperature. A loading of only 0.1–0.2 mol-% of derivative 1c was employed in this catalytic system, and excellent enantioselectivities and yields (up to 98 % yield, >99 % ee) could be achieved in aqueous media.

A series of novel organotin-containing core-cross-linked knedels and shell-cross-linked knedels were first synthesized facilely from poly(styrene)-b-poly(acrylate acid) nanoparticles in different selective solvents [Tetrahydrofuran (THF)/H₂O or THF/n-octane] by using organotin compound 1,3-dichloro-tetra-n-butyl-distannoxane as a new cross-linker. The formation of the 1-chloro-3-carboxylato-tetra-n-butyl-distannoxane layer in our cross-linking reaction was supported by Fourier transform infrared (FT-IR) and inductive coupled plasma emission spectrometer (ICP) analysis of the resulting shell-cross-linked knedels and core-cross-linked knedels. Transmission electron microscopy (TEM) study showed the spherical morphology and the size of the core-cross-linked knedels and shell-cross-linked knedel. Especially, the layer structure of the core-cross-linked knedels was clearly displayed in TEM image. The increase of extent of cross-linking lead to the increasing of diameter for the shell-cross-linked knedels, whereas there was no significant effect on the core-cross-linked knedels. Dynamic light scattering (DLS) measurements gave hydrodynamic diameters of the core-cross-linked knedels that were in agreement with the TEM diameters. Moreover, the wall thickness of the shell layer of the core-cross-linked knedels could be easily modified by varying the block copolymer composition. Notably, the organotin-containing core-cross-linked knedel exhibited highly efficient catalytic activity for the aqueous esterification reaction under nearly neutral conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010