5894-79-1Relevant articles and documents
Insertion of Alkylidene Carbenes into B-H Bonds
Yang, Ji-Min,Guo, Feng-Kai,Zhao, Yu-Tao,Zhang, Qiao,Huang, Ming-Yao,Li, Mao-Lin,Zhu, Shou-Fei,Zhou, Qi-Lin
supporting information, p. 20924 - 20929 (2020/12/23)
We have developed a protocol for insertion of alkylidene carbenes into the B-H bonds of amine-borane adducts, enabling, for the first time, the construction of C(sp2)-B bonds by means of carbene-insertion reactions. Various acyclic and cyclic alkenyl borane-amine adducts were prepared from readily accessible starting materials in good to high yields and were subsequently subjected to a diverse array of functional group transformations. The unprecedented spiro B-N heterocycles prepared in this study have potential utility as building blocks for the synthesis of pharmaceuticals. Preliminary mechanistic studies suggest that insertion of the alkylidene carbenes into the B-H bonds of the amine-borane adducts proceeds via a concerted process involving a three-membered-ring transition state.
A new method for preparing ipratropine (by machine translation)
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Paragraph 0041, (2017/09/02)
The invention discloses a ipratropine preparation method, comprises the following steps: benzene acetic acid methyl ester (III) as the starting material, the reaction process for preparing substituted α - formyl benzene acetic acid methyl ester (IV); tropine is mellow with methyl bromide reaction to prepare the compound (II); compound (II) with a compound (IV) reaction of compounds (V), compound (V) reduction process of preparing ipratropine anhydride, through the refining preparation ipratropine (VII), the method is simple in operation, high safety, low cost, is more suitable for industrial production. (by machine translation)
Diastereospecific nazarov cyclization of fully substituted dienones: Generation of vicinal all-carbon-atom quaternary stereocenters
Jolit, Anais,Vazquez-Rodriguez, Saleta,Yap, Glenn P. A.,Tius, Marcus A.
supporting information, p. 11102 - 11105 (2013/10/22)
No vacancy: Fully substituted dienones that are highly polarized by a vinylogous carbonate group were found to undergo a remarkably rapid and diastereospecific Nazarov cyclization that led to cyclopentenones with vicinal all-carbon-atom quaternary centers (see example; SEM=2-(trimethylsilyl) ethoxymethyl, Tf=trifluoromethanesulfonyl). Copyright