N-Substituted tertiary and O-substituted quaternary carbon stereogenic centers by site-, diastereo- and enantioselective vinylogous Mannich reactions.
N-Substituted tertiary and O-substituted quaternary carbon stereogenic centers by site-, diastereo- and enantioselective vinylogous Mannich reactions.
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DOI：
10.1016/j.tetlet.2015.04.006
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发表时间：
2015-06-03
影响因子：
1.8
通讯作者：
Hoveyda AH
中科院分区：
文献类型：
--
作者：
Silverio DL;Fu P;Carswell EL;Snapper ML;Hoveyda AH
一种容易获得的小分子膦，来源于商业上可获得的原料，如对映体纯氨基酸，作为ag基手性复合物的前体，可以原位制备和使用，以促进包括硅氧吡啶作为反应伙伴的各种对映选择性vinylogous Mannich （EVM）反应。未取代的亲核成分转化效率高，具有特殊的位点选择性（γ对α加成）、非对映体选择性和对映体选择性[收率高达98%，γ/α和非对映体比（dr）一般为98:2，对映体比（er）高达99:1]。第一个有效的，非映对和对映选择性的5-甲基取代的硅氧呋喃的vinyous Mannich加成，导致形成o取代的季碳立体中心的例子也被提出。具有明显的效率和非映体和对映体选择性（高达>98:2 dr和>99:1 er），并伴有可氧化去除的α-加成产物的形成
A readily accessible small-molecule phosphine, derived from commercially available starting materials such as an enantiomerically pure amino acid, serves as the precursor to a Ag-based chiral complex that can be prepared and used in situ to promote a variety of enantioselective vinylogous Mannich (EVM) reactions that involve siloxypyrroles as reaction partners. Transformations with unsubstituted nucleophilic components proceed efficiently and with exceptional site- (γ vs α-addition), diastereo- and enantioselectivity [up to 98% yield, generally >98:2 γ/α and diastereomeric ratio (dr) and up to 99:1 enantiomeric ratio (er)]. The first examples of efficient, diastereo- and enantioselective vinylogous Mannich additions with 5-methyl-substituted siloxyfuran, resulting in the formation of O-substituted quaternary carbon stereogenic centers are presented as well. Appreciable efficiency and diastereo- and enantioselectivity (up to >98:2 dr and >99:1 er) is accompanied by formation of α-addition products that can be oxidatively removed
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影响因子：
15
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
3.6
作者：
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通讯作者：
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