The Masuda borylationâSuzuki 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 1H-pyrazoles in the fashion of a three-step one-pot procedure consisting of a Masuda borylationâSuzuki coupling and subsequent Michael additionâcyclocondensationâelimination sequence.
Masuda borylationâSuzuki 偶联(
MBSC)序列成功地扩展到了使用立体受阻膦烷
配体的
乙烯基卤化物与各种(杂)芳基卤化物的高难度偶联。从(杂)芳基卤化物和δ-
溴肉桂醛开始,在 Pd 催化下依次选择性地生成δ、δ² 取代的
肉桂醛,而不会影响迈克尔体系的反应活性。这些中间体作为新合成 3,4-二芳基 1H-
吡唑的入口,采用三步一步法合成,包括 Masuda 玻里化-铃木偶联和随后的迈克尔加成-环缩合-消除顺序。