CORNERSTONE WORKS FOR CATALYTIC 1,3-DIPOLAR CYCLOADDITION REACTIONS
CORNERSTONE WORKS FOR CATALYTIC 1,3-DIPOLAR CYCLOADDITION REACTIONS
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DOI：
10.3987/rev-10-666
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发表时间：
2010-12-31
期刊：
影响因子：
0.6
通讯作者：
Kanemasa, Shuji
中科院分区：
文献类型：
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作者：
Kanemasa, Shuji
本文综述了以下内容：（1）研究了含金属原子的N-金属甲亚胺叶立德作为一种新的1，3-偶极化合物的化学。这种由（N-亚烷基氨基）链烷酸酯在用刘易斯酸和胺碱处理后产生的1，3-偶极，经历向缺电子烯烃的快速1，3-偶极环加成。特别是，α，β-不饱和羰基底物显示出高速率加速，以高度区域选择性和内选择性的方式得到吡咯烷-2，4-二羧酸酯。(2)通过改变底物结构和反应条件，可以将（N-亚烷基氨基）乙酸酯的1，3-偶极环加成反应转变为反选择性Michael加成反应。(3)两种类型的杂环手性助剂被证明为不对称的1，3-偶极环加成反应。一种类型连接在α，β-不饱和酯的β-位上。所得到的手性α，β-不饱和酯被成功地应用于N-金属甲亚胺叶立德的立体选择性不对称环加成反应。其他类型包括4-苄基-2，2，5，5-四甲基恶唑烷-3-丙烯酰胺，其基于丙烯酰胺反应位点的构象控制和4-苄基氨基的空间屏蔽。这些都适用于绝对不对称的氧化腈环加成反应。(4)在刘易斯酸催化下，实现了硝酮与缺电子烯烃的环加成反应。这提供了1，3-偶极环加成的第一个催化立体控制。(5)氧化腈与烯丙醇醇镁的1，3-偶极环加成反应的极有效速率增强。观察到的最大速率提高是未催化反应的16，000倍速率加速。该方法首次成功地加速了腈氧化物1，3-偶极环加成反应。(6)烯丙基醇的烷氧基镁的使用在硝酮1，3-偶极环加成中也是高度有效的，导致高立体选择性和区域选择性。(7)催化对映选择性的1，3-偶极环加成是通过使用硝酮，硝膦酸盐，重氮甲烷，和腈氧化物的存在下，耐受的手性催化剂的基础上，我们的R，R-DBFOX/Ph配体。
This review covers the following subjects: (1) The chemistry of N-metalated azomethine ylide as a new 1,3-dipole containing a metal atom is studied. This 1,3-dipole, generated from (N-alkylideneamino)alkanoates upon treatment with a Lewis acid and amine base, undergoes rapid 1,3-dipolar cycloadditions toward electron-deficient alkenes. Especially, alpha,beta-unsaturated carbonyl substrates show high rate acceleration to give pyrrolidine-2,4-dicarboxylates in a highly regio- and endo-selective manner. (2) This 1,3-dipolar cycloaddition reaction of (N-alkylideneamino)acetate can be switched into anti-selective Michael addition reaction by modification of substrate structures as well as reaction conditions. (3) Two types of heterocyclic chiral auxiliaries are demonstrated for the asymmetric 1,3-dipolar cycloadditions. One types are attached at the beta-position of alpha,beta-unsaturated esters. The resulting chiral alpha,beta-unsaturated esters are successfully applied to the stereoselective asymmetric cycloadditions of N-metalated azomethine ylides. The other types include 4-benzy1-2,2,5,5-tetramethyloxazolidine-3-acrylamides which are based on the conformational control of the acrylamide reaction site and that of steric shielding of 4-benzyl amoiety. These are applied to the absolutely asymmetric nitrile oxide cycloadditions. (4) The nitrone cycloadditions to electron-deficient alkenes is attained in the presence of a Lewis acid catalyst. This provides the first catalytic stereo control of 1,3-dipolar cycloadditions. (5) The extremly effective rate enhancement of nitrile oxide 1,3-dipolar cycloadditions to the magnesium alkoxides of allylic alcohols. Maximum rate enhancement observed is 16,000 fold rate acceleration of the uncatalyzed reaction. This method offers the first successful rate acceleration in nitrile oxide 1,3-dipolar cycloadditions. (6) Use of magnesium alkoxide of allylic alcohols is also highly effectve in nitrone 1,3-dipolar cycloadditons, resulting in high stereo- and regioselectivities. (7) Catalytic enantioselective 1,3-dipolar cycloadditions are achieved by use of nitrones, nitronates, diazomethane, and nitrile oxides in the presence of tolerant chiral catalysts based on our R,R-DBFOX/Ph ligand.