完整版化学专业英语摘要翻译6篇.doc

大学英语
AsymmetricC(sp)-C(sp2)bondformationtogiveenantiomericallyenriched1,3-butadienyl-2-carbinolsoccurredthroughahomoallenylborationreactionbetweena2,3-dienylboronicesterandaldehydesunderthecatalysisofachiralphosphoricacid(CPA).Adiverserangeofenantiomericallyenrichedbutadiene-substitutedsecondaryalcoholswitharyl,heterocyclic,andaliphaticsubstituentsweresynthesizedinveryhighyieldwithhighenantioselectivity.Preliminarydensityfunctionaltheory(DFT)calculationssuggestthatthereactionproceedsviaacyclicsix-memberedchairliketransitionstatewithessentialhydrogen-bondactivationintheallenereagent.Thecatalyticreactionwasamenabletothegram-scalesynthesisofachiralalkylbutadienyladduct,whichwasconvertedintoaninterestingopticallypurecompoundbearingabenzo-fusedspirocycliccyclopentenoneframework.

在手性磷酸（CPA）催化剂条件下，2,3-硼酸酯和醛通过反应生成了富对映体的1,3-丁二烯-2-甲醇，这里面含有不对称的碳（sp杂化）碳（sp2杂化）键。不同丁二烯取代的二级醇的富对映体和芳香烃、杂环以及脂肪烃的合成可以有高产率和很好的对映体选择性。初步的密度泛函理论（DFT）的计算表明，这个反应是在丙二醇试剂中通过对氢键必要的活化而经过了一个六元环椅型结构的过渡态实现的。这个反应对于手性的烷基二烯的克级别反应而言是容易控制的，而手性的烷基二烯可以转化为一种有趣的耐苯并环戊酮的光学纯化合物。

YiyongHuang,XingYang,ZongchaoLv,ChenCai,ChengKai,YongPei,andYuFeng.AsymmetricSynthesisof1,3-Butadienyl-2-carbinolsbytheHomoallenylborationofAldehydeswithaChiralPhosphoricAcidCatalyst[J].AngewandteChemie,2015,127:7407-7410

C-Hbondsareubiquitousinorganiccompounds.Itwould,therefore,appearthatdirectfunctionalizationofsubstratesbyactivationofC-Hbondswouldeliminatethemultiplestepsandlimitationsassociatedwiththepreparationoffunctionalizedstartingmaterials.RegioselectivityisanimportantissuebecauseorganicmoleculescancontainawidevarietyofC-Hbonds.TheuseofadirectinggroupcanlargelyovercometheissueofregiocontrolbyallowingthecatalysttocomeintoproximitywiththetargetedC-Hbonds.AwidevarietyoffunctionalgroupshavebeenevaluatedforuseasdirectinggroupsinthetransformationofC-Hbonds.In2005,DaugulisreportedthearylationofunactivatedC(sp(3))-Hbondsbyusing8-aminoquinolineandpicolinamideasbidentatedirectinggroups,withPd(OAc)2asthecatalyst.Encouragedbythesepromisingresults,