Masuda borylation-Suzuki coupling (MBSC) sequence of vinylhalides and its application in a one-pot synthesis of 3,4-biarylpyrazolesElectronic supplementary information (ESI) available: Experimental details of the syntheses and analytical details of the compounds 3, 5, and 7. See DOI: 10.1039/c3ob41249k

The Masuda borylation-Suzuki coupling (MBSC) sequence was successfully extended to the challenging coupling of vinylhalides with various (hetero)arylhalides using sterically hindered phosphane ligands. Starting from (hetero)arylhalides and α-bromocinnamaldehyde, the sequentially Pd-catalyzed process selectively furnishes α,β-substituted cinnamaldehydes without affecting the reactivity of the Michael system. These intermediates were implemented as entries into a novel synthesis of 3,4-diaryl 1 H -pyrazoles in the fashion of a three-step one-pot procedure consisting of a Masuda borylation-Suzuki coupling and subsequent Michael addition-cyclocondensation-elimination sequence. The Masuda borylation-Suzuki coupling (MBSC) sequence can be successfully extended to the coupling of vinylhalides with various (hetero)arylhalides. 3,4-Diaryl 1 H -pyrazoles are readily accessible in a one-pot three-component procedure starting from (hetero)arylhalides and α-bromocinnamaldehyde.