Palladium-Catalyzed Isomerization/Hydrocarbonylation of Electron-Deficient Alkenes for the Construction of Lactones and Lactams.

An efficient palladium-catalyzed isomerization/hydrocarbonylation of electron-deficient alkenes was developed, affording a variety of benzofuran-2(3)-ones, dihydrofuran-2(3)-ones, indolin-2-ones, and isochroman-3-ones in high yields. The reaction exhibits excellent regioselectivity, high atom economy, and a broad range of substrates. The late-stage modification of bioactive molecules and scaled-up reaction demonstrated the practicability of this methodology.

Palladium-Catalyzed Asymmetric Larock Isoquinoline Synthesis to Access Axially Chiral 3,4-Disubstituted Isoquinolines.

Larock isoquinoline synthesis is one of the most efficient and straightforward approaches to the construction of 3,4-disubstituted isoquinolines. However, there have been no asymmetric versions for the synthesis of axially chiral isoquinolines since their initial report in 2001. Herein, we documented the first example of an asymmetric Larock isoquinoline synthesis by employing Pd(OAc)/Walphos SL-W002-1 as the catalyst, affording the axially chiral 3,4-disubstituted isoquinolines with up to 97.

Rhodium-Catalyzed Selective Nucleophilic Cyclization/Cross-Coupling of Two -Alkynylanilines Bearing Differential -Substituents.

Herein, we reported an effective selective nucleophilic cyclization/cross-coupling cascade reaction of -tosyl -alkynylanilines and -acyl -alkynylanilines using Rh(COD)BF/BuXantPhos as a catalyst. The present protocol features excellent chemo- and regioselectivity, high atom-economy, and a broad range of substrates. The mechanism studies indicated that the key to the success of this reaction is the powerful capacity of the rhodium catalyst to recognize the -substituent group in the selective nucleophilic cyclization and selective alkyne insertion.

The stereoselective conversion of epimerized alkoxyl phosphine-borane to -stereogenic tertiary phosphine cleavage of P-O bond.

The P-O bond of epimerized alkoxyl phosphine-borane was cleaved by naphthalene-lithium, to form two diastereomers of P-anions in a ratio of 86 : 14, which was then converted to secondary phosphine-borane acidification, and to tertiary phosphines with alkyl halides with enhanced 96 : 4 dr. The isolated tertiary phosphine containing hydroxyl (in >99 : 1 dr) was converted to multi-stereogenic tertiary phosphines -alkylation with alkylene dihalides.

Cleavage of Aromatic C-O Bonds via Intramolecular SAr Reaction and Preparation of ,,-Stereogenic Menthyl Phosphine Derivatives.

Phosphine ligands with up to six chiral sites were prepared, starting from 2-phenylphenol, via - and -alkylation, cyclization, and coupling. The chirality was transferred from ()-menthyl to phosphorus, α-carbon, and axis, to achieve excellent diastereoselectivities. During an intramolecular SAr reaction with alkoxyl as the leaving groups, the C-O bond was converted to a C-C bond.

Stereoselective preparation of P,axial-stereogenic allenyl bisphosphine oxides via chirality-transfer.

P,C-Stereogenic propargyl alcohols RC-3/SC-3' were prepared by the addition of (L)-menthyl-derived SPOs to propynals, which were converted to P,axial-stereogenic allenyl bisphosphine oxides. The chirality transfer was controlled by α-carbon via syn [2,3]-sigmatropic rearrangement. For SC-3' linking weak WDG on the alkynyl moiety, the chirality on the axis depended on stereogenic phosphorus.