Enzymatic Strategy for the Resolution of New 1-Hydroxymethyl Tetrahydro-<i>β</i>
-carboline Derivatives in Batch and Continuous-Flow Systems
作者:Rita Megyesi、Enikő Forró、Ferenc Fülöp
DOI:10.1002/open.201500203
日期:2016.6
o‐1,2,3,4‐tetrahydro‐β‐carboline [(±)‐9] were prepared through enzymecatalyzed asymmetric acylation of their primary hydroxyl group. The preliminary experiments were performed in a continuous‐flow system, while the preparative‐scale resolutions were done as batch reactions. Excellent enantioselectivities (E>200) were obtained with Candida antarctica lipase B (CAL‐B) and acetic anhydride in toluene
许多含有四氢-β-咔啉骨架的生物碱具有众所周知的治疗作用,从而引起人们对这些天然产物合成的兴趣增加。N -Boc保护的1-羟甲基-1,2,3,4-四氢-β-咔啉的对映体[(±)-7 ],1-羟甲基-6-甲氧基-1,2,3,4-四氢β-咔啉[(±)-8 ]和1-羟甲基-6-氟-2-1,2,3,4-四氢-β-咔啉[(±)-9通过酶催化的伯羟基的不对称酰化反应制备了[α]。初步实验是在连续流系统中进行的,而制备规模的拆分是作为间歇反应进行的。在60°C的甲苯溶液中,南极假丝酵母脂肪酶B(CAL-B)和乙酸酐获得了优异的对映选择性(E > 200)。具有高对映体过量的值(获得回收的醇和所产生的酯EE ≥96%)。将O-酰化对映体[(S)‐10 –(S)‐12)]转化为相应的氨基醇[(S)‐7 –(S)‐ 9)]进行甲醇分解。微波辅助的Boc清除还进行并导致相应的化合物中([R )- 4 - ([R