CAJ | 학술논문

采用K3PO4×3H2O修饰的Pd/C为催化剂实现了取代四氢异喹啉高选择性部分脱氢,并成功地避免了当量有害氧化剂的使用。多相催化剂Pd/C对四氢异喹啉化合物具有催化脱氢活性,但反应选择性较差,同时产生完全脱氢的芳构化产物异喹啉。而K3PO4×3H2O修饰的Pd/C催化剂能有效提高脱氢反应的化学选择性,在最优条件下可获得最高89%的分离收率。这为取代3,4-二氢异喹啉的合成提供了一种简便、高原子经济性和高化学选择性的反应途径。此外,该多相催化剂可回收循环使用多次,且活性和选择性基本保持不变。
채용K3PO4×3H2O수식적Pd/C위최화제실현료취대사경이규람고선택성부분탈경,병성공지피면료당량유해양화제적사용。다상최화제Pd/C대사경이규람화합물구유최화탈경활성,단반응선택성교차,동시산생완전탈경적방구화산물이규람。이K3PO4×3H2O수식적Pd/C최화제능유효제고탈경반응적화학선택성,재최우조건하가획득최고89%적분리수솔。저위취대3,4-이경이규람적합성제공료일충간편、고원자경제성화고화학선택성적반응도경。차외,해다상최화제가회수순배사용다차,차활성화선택성기본보지불변。
A highly selective procedure has been developed for the partial dehydrogenation of 1‐substitut‐ed‐1,2,3,4‐tetrahydroisoquinolines over K3PO4×3H2O‐modified Pd/C catalyst. This new method provides facile, atom‐economical and environmentally friendly access to 1‐substituted‐3,4‐dihy‐droisoquinolines without the need for stoichiometric amounts of harmful oxidants. The use of standard Pd/C as a catalyst for this process gave poor chemoselectivity. Pleasingly, the use of a K3PO4×3H2O‐modified Pd/C catalyst promoted the partial dehydrogenation of 1‐substituted‐1,2,3,4‐tetrahydroisoquinolines with excellent chemoselectivity by suppressing further dehydroaromatiza‐tion. Furthermore, conducting the reaction under an atmosphere of oxygen led to further improve‐ments in the chemoselectivity of the dehydrogenation, with the ratio of imine to isoquinoline reaching up to 32/1. The heterogenous Pd/C catalyst could also be recycled and reused at least three times with excellent conversion and chemoselectivity, demonstrating the significantly practi‐cal potential of this methodology.