Stable and Persistent Acyclic Diaminocarbenes with Cycloalkyl Substituents and Their Transformation to β-Lactams by Uncatalysed Carbonylation with CO.
Stable and Persistent Acyclic Diaminocarbenes with Cycloalkyl Substituents and Their Transformation to β-Lactams by Uncatalysed Carbonylation with CO.
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具有环烷基取代基的稳定且持久的无环二氨基卡宾及其通过CO非催化羰基化转化为β-内酰胺
DOI：
10.1002/chem.201805307
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发表时间：
--
期刊：
影响因子：
--
通讯作者：
U. Siemeling
中科院分区：
文献类型：
--
作者：
L. Wallbaum;D. Weismann;D. Löber;C. Bruhn;P. Prochnow;J. E. Bandow;U. Siemeling
通过六氟磷酸甲脒盐与NaN（SiMe 3）2反应，合成了4个新的无环二氨基卡宾（阿达克斯）[（cyclo-CnH 2n −1）2N]2C（n=5-7）和Pr 2N-C-N（cyclo-C6 H11）2.它们的亲核性和亲电性分别由相应甲脒阳离子N2 CH单元的1 JCH值和元素硒与相应阿达克斯反应得到的硒脲衍生物的77 Se NMR化学位移来判断。在每种情况下发现与“桤木卡宾”（iPr 2N）2C基本相同的两亲性特征。与后者卡宾类似，新的阿达克斯通过β-断裂进行明确的热分解，得到烯烃和甲脒。[（cyclo-CnH 2n −1）2N]2C的稳定性强烈地依赖于n的值，遵循6>5>7的顺序，后者的同系物太不稳定而无法分离。[（cyclo-C6 H11）2N]2C在室温下在溶液中没有热分解，因此比（iPr 2N）2C稳定得多。iPr 2N-C-N（cyclo-C6 H11）2的稳定性介于（iPr 2N）2C和[（cyclo-C6 H11）2N]2C之间，其β-断裂选择性地提供丙烯和PrN = CH-N（cyclo-C6 H11）2。[（cyclo-CnH 2n −1）2N]2C（n=5-7）在温和条件下容易与CO反应，选择性地得到具有与青霉素G相似的抗菌活性谱的三取代螺环β-内酰胺衍生物。
Four new acyclic diaminocarbenes (ADACs), viz. [(cyclo‐CnH2n−1)2N]2C (n=5–7) andiPr2N‐C‐N(cyclo‐C6H11)2, were synthesised by reacting the corresponding formamidinium hexafluorophosphates with NaN(SiMe3)2. Their nucleophilicities and electrophilicities were respectively judged from the1JCHvalues determined for the N2CH unit of the corresponding formamidinium cations and from the77Se NMR chemical shifts of the selenourea derivatives obtained from the reaction of elemental selenium with the corresponding ADACs. An ambiphilic profile essentially identical to that of the “Alder carbene” (iPr2N)2C was found in each case. Similar to the latter carbene, the new ADACs undergo a well‐defined thermal decomposition by β‐fragmentation, affording an alkene and a formamidine. The stabilities of [(cyclo‐CnH2n−1)2N]2C depend strongly on the value ofn, following the order 6>5>7, with the latter congener being too unstable for isolation. [(cyclo‐C6H11)2N]2C shows no thermal decomposition at room temperature in solution and is thus significantly more stable than (iPr2N)2C. The stability ofiPr2N‐C‐N(cyclo‐C6H11)2is intermediate between that of (iPr2N)2C and [(cyclo‐C6H11)2N]2C, its β‐fragmentation selectively affording propene andiPrN=CH‐N(cyclo‐C6H11)2. [(cyclo‐CnH2n−1)2N]2C (n=5–7) react readily with CO under mild conditions, selectively affording trisubstituted spirocyclic β‐lactam derivatives with an antimicrobial activity spectrum similar to that of penicillin G.
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影响因子：
16.6
作者：
Lavallo, Vincent;Canac, Yves;Bertrand, Guy
通讯作者：
Bertrand, Guy
无环二氨基卡宾钯配合物催化的铃木反应中芳基、烷基和环烷基卤化物的活性比较
影响因子：
0.9
作者：
S. A. Kras’ko;S. S. Zlotskii;V. P. Boyarskii
通讯作者：
V. P. Boyarskii
固定在聚合物载体上的手性无环二氨基卡宾络合物作为铃木反应的有前途的催化剂
影响因子：
0.9
作者：
V. N. Mikhailov;K. Korvinson;V. N. Sorokoumov
通讯作者：
V. N. Sorokoumov
正常和异常（介离子）N-杂环卡宾的电子和配体特性：理论研究。
DOI：
10.1021/jo402057g
发表时间：
2013
期刊：
The Journal of organic chemistry
影响因子：
--
作者：
A. K. Phukan;A. Guha;S. Sarmah;Rian D. Dewhurst
通讯作者：
Rian D. Dewhurst
比较积烯取代基效应：通过从头算分子轨道计算乙烯酮、丙二烯、重氮甲烷、二氮丙啶和环丙烯
影响因子：
3.6
作者：
M. McAllister;T. Tidwell
通讯作者：
T. Tidwell