Confinement-Controlled, Either syn- or anti-Selective Catalytic Asymmetric Mukaiyama Aldolizations of Propionaldehyde Enolsilanes.
Confinement-Controlled, Either syn- or anti-Selective Catalytic Asymmetric Mukaiyama Aldolizations of Propionaldehyde Enolsilanes.
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DOI：
10.1021/jacs.1c07447
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发表时间：
2021-09-15
影响因子：
15
通讯作者：
List B
中科院分区：
文献类型：
--
作者：
Amatov T;Tsuji N;Maji R;Schreyer L;Zhou H;Leutzsch M;List B
具有顺式或反式立体化学的受保护醛醇（即，源自醛的真正醛醇）是许多低丙酸酯合成中的通用中间体。此类羟醛的传统立体选择性方法通常需要一些非战略操作。在这里，我们报道了丙醛的TBS-或TES-烯醇硅烷与芳香醛的两种高度对映选择性和非对映选择性催化Mukaiyama羟醛反应。我们的反应以催化剂控制的方式直接提供有价值的甲硅烷基保护的丙醛羟醛，无论是顺式异构体还是反式异构体。我们已经确定了一种独特的 IDPi 催化剂基序，专门用于以卓越的选择性控制这些醛醇缩合反应。我们展示了 IDPi 催化剂内核中的单原子修饰（用 CF2H 基团取代 CF3 基团）如何导致醛的对映面分化发生巨大转变。这种显着效果的根源在于通过 CF2H 基团的非常规 C-H 氢键使催化空腔收紧。
Protected aldols (i.e., true aldols derived from aldehydes) with either syn- or anti- stereochemistry are versatile intermediates in many oligopropionate syntheses. Traditional stereoselective approaches to such aldols typically require several nonstrategic operations. Here we report two highly enantioselective and diastereoselective catalytic Mukaiyama aldol reactions of the TBS- or TES- enolsilanes of propionaldehyde with aromatic aldehydes. Our reactions directly deliver valuable silyl protected propionaldehyde aldols in a catalyst controlled manner, either as syn- or anti- isomer. We have identified a privileged IDPi catalyst motif that is tailored for controlling these aldolizations with exceptional selectivities. We demonstrate how a single atom modification in the inner core of the IDPi catalyst, replacing a CF3-group with a CF2H-group, leads to a dramatic switch in enantiofacial differentiation of the aldehyde. The origin of this remarkable effect was attributed to tightening of the catalytic cavity via unconventional C–H hydrogen bonding of the CF2H group.
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影响因子：
16.6
作者：
Gatzenmeier, Tim;Kaib, Philip S. J.;List, Benjamin
通讯作者：
List, Benjamin
影响因子：
3.6
作者：
Crimmins, MT;King, BW;Chaudhary, K
通讯作者：
Chaudhary, K
影响因子：
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作者：
Kano, Taichi;Yamaguchi, Yukako;Maruoka, Keiji
通讯作者：
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影响因子：
15
作者：
Kim, Hyunwoo;Ho, Stephen;Leighton, James L.
通讯作者：
Leighton, James L.
影响因子：
56.9
作者：
HEATHCOCK, CH
通讯作者：
HEATHCOCK, CH