Borane-catalyzed one-pot tandem cyclization/hydrosilylation of levulinic acid and other γ-keto acids with hydrazines for selective access to hexahydropyridazines and tetrahydropyridazin-3(2H)-ones has been developed. The combination of B(C₆F₅)₃ and Et₃SiH allows for synthesis of various hexahydropyridazines and tetrahydropyridazin-3(2H)-ones in 67–97% yields with tolerance towards various functional groups and easy scale-up. This reaction can be rendered enantioselective by using a chiral borane catalyst generated in situ from HB(C₆F₅)₂ and a binaphthyl-based chiral diene and PhMe₂SiH, affording the target products in 70–92% yields with up to >99% ee. The judicious choice of borane catalyst and hydrosilane reductant proves to be critical for catalysis. Mechanistic investigations elucidate the catalytic pathway.

已经开发了硼烷催化的乙酰丙酸和其他γ酮酸与肼的一锅串联环化/氢化硅烷化反应，用于选择性获得六氢吡哒嗪和四氢吡哒嗪-3（2H）-酮。B（C₆， F₅）₃ 和 Et₃， SiH 的组合允许以 67–97% 的产率合成各种六氢吡哒嗪和四氢吡哒嗪-3（2H）-酮，并且对各种官能团具有耐受性，易于放大。通过使用由 HB（C₆F₅）₂ 原位生成的手性硼烷催化剂和二氢基手性二烯和 PhMe₂SiH，该反应可以达到对映选择性，从而以 70-92% 的收率获得目标产物，EE 含量高达 >99%。事实证明，硼烷催化剂和氢硅烷还原剂的明智选择对于催化至关重要。机理研究阐明了催化途径。