Zn–ZrO2/SSZ-13 catalyzed direct conversion of syngas into lower olefins via methanol/DME intermediates with 77% selectivity at 29% CO conversion.

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The first example of Pd -catalyzed enantioselective C-H olefination with non-chiral or racemic sulfoxides as directing groups was developed. A variety of chiral diaryl sulfoxides were synthesized with high enantioselectivity (up to 99 %) through both desymmetrization and parallel kinetic resolution (PKR). This is the first report of Pd -catalyzed enantioselective C(sp )-H functionalization through PKR, and it represents a novel strategy to construct sulfur chiral centers.

An azaborine-based phosphine-Pd catalystw as introduced by the Liu group to promote trans hydroboration of the C Ct riple bond of internal 1,3-enyne substrates. Despite the excellent yield and selectivity observed experimentally,t he mechanism and the origin of this special trans selectivity remained unknown. Herein, ac omprehensive theoretical investigation was performed to clarify these issues. Accordingly,t wo main mechanisms (inner-and outersphere) were proposed and examined. Different from the conventionali nner-sphere mechanism,i nw hich the transition metal is involved in HÀBb ond cleavage, this reaction follows an outer-sphere mechanism, in which Pd does not directlyp articipate in HÀBb ond cleavage. More specifically, the favorable pathway followed aT suji-Trost type reaction, in which the HÀBb ond was weakened by the formation of a four-coordinate boron intermediate (i.e.,t he boron is attached to the terminalc arbon of the alkyne group). It then underwent ah ydride-transfer process with the assistance of as econd borane molecule, and finally reductivee limination generated the trans hydroboration product. Further analysis ascribed the origin of the special trans selectivity to the unique steric effect and electronic effect introduced by the special k 1 -P-h 2 -BC coordinationpattern.

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A substrate-assisted diboration of alkynamides using the unsymmetrical pinacolato-1,8-diaminonaphthalenato diboron (pinBBdan) is described. The transition-metal-free reaction proceeds in a regio- and stereoselective fashion to exclusively afford trans-vinyldiboronates in good to excellent yields. Notably, Bdan and Bpin are installed on the α- and β-carbon atoms, respectively.