Chelation-Controlled Stereospecific Cross-Coupling Reaction between Alkenes for Atroposelective Synthesis of Axially Chiral Conjugated Dienes.

In this protocol, an efficient palladium-catalyzed asymmetric synthesis of axially chiral conjugated dienes via alkenyl C-H olefination is reported. The corresponding atropisomeric styrenes containing a conjugated diene scaffold were obtained in good yields with good enantioselectivities. This synthetic strategy features an easy operation, mild reaction conditions, a wide functionality tolerance, and high efficiency.

Synthesis of Allenyl-Bdan via Cu(I)-Catalyzed Borylation of Propargyl gem-Dichlorides.

A copper-catalyzed borylation of propargyl dichlorides was developed under mild reaction conditions. The corresponding chloro-substituted allenyl-Bdan products were obtained in good yields. The utilities of allenyl-Bdan products were examined by their diverse derivatizations.

Synthesis of Enynic and Allenic Orthoesters via Defluoromethoxylation of 2-Trifluoromethyl-1,3-enynes.

In this protocol, the chemoselective defluoromethoxylation reactions of 2-trifluoromethyl-1,3-enynes were developed. The enynic and allenic orthoesters were selectively produced in good to excellent yields via multiple substitution processes under mild reaction conditions, respectively. The enynic orthoester products were proved capable of acting as efficient "platform molecules" to access various functionalized allenyl compounds.

Catalytic Asymmetric Conjugate Protosilylation and Protoborylation of 2-Trifluoromethyl Enynes for Synthesis of Functionalized Allenes.

The Cu-catalyzed 1,4-protosilylation and protoborylation of trifluoromethyl-substituted conjugated enynes were developed to access functionalized homoallenylsilanes and homoallenylboronates. This protocol also provides a general method to synthesize optically active homoallenylsilanes and homoallenylboronates in moderate to excellent yields with high enantiomeric excess by using new designed chiral bisoxazoline ligands. Simultaneously, the transformations of homoallenylsilanes and homoallenylboronates were also explored to synthesize useful building blocks.

Palladium-Catalyzed Dialkylation of C-C Triple Bonds: Access to Multi-Functionalized Indenes.

A palladium-catalyzed dialkylation of 1,3-dien-5-ynes was developed using alkenyl double bonds as the initiator and terminator for the synthesis of functionalized indene derivatives. The reactions were performed under mild reaction conditions, affording the corresponding multi-substituted indene derivatives in high efficiency via unprecedented 5- endo cyclization and alkylation processes. It was found that the substituent location at the alkenyl double bond was essential for the chemoselective synthesis of the indene and naphthalene derivatives, respectively.