权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of new function of N-oxide based on the electron-donating property of oxide oxygen

基于氧化物氧的给电子特性开发N-氧化物新功能

基本信息

批准号：
13672204
负责人：
NAKAJIMA Makoto
金额：
$ 2.18万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

Although it is well documented that amine N-oxides act as powerful electron-pair donors to form complexes with a variety of acceptor molecules, synthetic utility of amine N-oxides as ligands or catalysts still remains to be developed. We have developed the following N-oxide-mediated organic reactions. 1.Optically active allenic and homopropargylic alcohols were selectively obtained by a chiral N-oxide-catalyzed reaction of aldehydes with propargyltrichlorosilane and allenyltrichlorosilane, prepared in situ from propargyl chloride. 2.An enantioselective ring opening of meso-epoxides with tetrachlorosilane in the presence of diisopropylethylamine exploiting chiral bipyridine N,N'-dioxides as catalysts affords the corresponding chlorohydrins in high enantioselectivities of up to 90% ee. 3.Chiral N,N'-dioxides and monodentate N-oxides were employed as catalysts in catalytic, enantioselective aldol reactions of trichlorosilyl enol ethers. The reactions of acyclic enol etheis using N,N'-dioxides resulted in the anti-adducts from (E)-enol ethers and the syn-adducts from (Z)-enol ethers. The reactions of cyclic (E)-enol ethers using N,N'-dioxides gave the anti-adducts, whereas monodentate N-oxides predominantly gave the syn-adducts. 4.Chiral N,N'-dioxide-cadmium iodide complex has been shown to catalyze enantioselective conjugate additions of thiols to cyclic enones and enals. The sulfides are generated in high yields and in good enantioselctivities up to 78% ee using 1 mol % of the chiral catalyst. The present reaction provides the first example of utilizing a cadmium complex as a catalyst in enantioselective reaction. 5.A catalytic, enantioselective Michael addition of β-keto esters to α,β-unsaturated carbonyl compounds was achieved by using a chiral biquinolme N,N'-dioxide-scandium trifluoromethanesulfonate complex as a catalyst. The corresponding Michael adducts were obtained in high yields and with enantioselectivities up to 84% ee.

尽管有充分证据表明，N-氧化物胺可作为强大的电子对供体与各种受体分子形成络合物，但N-氧化物胺作为配体或催化剂的合成用途仍有待开发。我们开发了以下 N-氧化物介导的有机反应。 1.通过手性N-氧化物催化的醛与炔丙基三氯硅烷和丙二烯基三氯硅烷的反应选择性地获得光学活性的丙二烯醇和均丙炔醇，其中丙二烯基三氯硅烷是由炔丙基氯原位制备的。 2.在二异丙基乙胺存在下，利用手性联吡啶N,N'-二氧化物作为催化剂，用四氯硅烷对内消旋环氧化物进行对映选择性开环，得到相应的氯代醇，对映选择性高达90% ee。 3.手性N,N'-二氧化物和单齿N-氧化物作为催化剂用于三氯硅基烯醇醚的催化、对映选择性羟醛反应。使用N,N'-二氧化物的无环烯醇醚反应产生(E)-烯醇醚的反加合物和(Z)-烯醇醚的顺式加合物。使用N,N'-二氧化物的环(E)-烯醇醚的反应产生反加合物，而单齿N-氧化物主要产生顺式加合物。 4.手性N,N'-二氧化物-碘化镉络合物已被证明可以催化硫醇与环烯酮和烯醛的对映选择性共轭加成。使用 1 mol% 的手性催化剂，硫化物的产率很高，对映选择性高达 78% ee。本反应提供了在对映选择性反应中利用镉络合物作为催化剂的第一个例子。 5.使用手性联喹啉N,N'-二氧化钪三氟甲磺酸钪络合物作为催化剂，实现了β-酮酯与α,β-不饱和羰基化合物的催化、对映选择性迈克尔加成。以高产率获得了相应的迈克尔加合物，对映选择性高达 84% ee。