A Facile and Efficient Approach to
<i>N</i>
‐Protected‐β‐Sulfinyl‐ enamines
<i>via C</i>
‐Sulfinylation of Enamides and Enecarbamates
作者:Yinhui Li、Ke Cheng、Xiaoxia Lu、Jian Sun
DOI:10.1002/adsc.201000084
日期:2010.10.9
A practical method has been developed for the C-sulfinylation of enamides and enecarbamates using sodium phenylsulfinate/methyltrichlorosilane (PhSO2Na/MeSiCl3) as the sulfinylating reagent and N,N-dimethylacetamide (DMAc) as the Lewis base promoter, which allows for the preparation of a variety of N-protected-β-sulfinylenamines in high yields and good stereoselectivities. The Lewis base is found to
已开发出一种实用的方法,使用苯磺酸钠/甲基三氯硅烷(PhSO 2 Na / MeSiCl 3)作为亚磺酰化试剂,并使用N,N-二甲基乙酰胺(DMAc)作为路易斯碱促进剂,对酰胺和烯氨基甲酸酯进行C-亚磺酰基化。以高收率和良好的立体选择性制备各种N-保护的β-亚磺酰亚胺胺。发现路易斯碱对于活性亚磺酰基化物质(PhSOC1)的原位生成和亚磺酰基化步骤均是重要的。
Highly Enantioselective Electrophilic α-Bromination of Enecarbamates: Chiral Phosphoric Acid and Calcium Phosphate Salt Catalysts
phosphoric acids and chiral calcium phosphates both catalyze highly enantio- and diastereoselective electrophilic α-bromination of enecarbamates to provide an atom-economical synthesis of enantioenriched vicinal haloamines. Either enantiomer can be formed in good yield with excellent diastereo- and enantioselectivity simply by switching the catalyst from a phosphoric acid to its calcium salt.
Regioselective Rh(I)-Catalyzed Sequential Hydrosilylation toward the Assembly of Silicon-Based Peptidomimetic Analogues
作者:Geanna K. Min、Troels Skrydstrup
DOI:10.1021/jo300904z
日期:2012.7.20
A highly regioselective Rh(I)-catalyzed hydrosilylation of enamides is presented. This mild protocol allows access to a wide variety of different arylsilanes with substitution at the beta-position of the enamide and functionalization on the alkyl chain tethered to the silane. This protocol is extended to include a sequential one-pot hydrosilylation. Using diphenylsilane as the appendage point, hydrosilylation of a protected allyl alcohol followed by hydrosilylation of an enamide generates a complex organosilane in one step. This highly convergent strategy to synthesize these functionalized systems now provides a way for the rapid assembly of a diverse collection of silane-based peptidomimetic analogues.
Trimethylchlorosilane-promoted aza-Mannich reaction of enecarbamates and aldimines
作者:Pengcheng Wu、Deqin Lin、Xiaoxia Lu、Li Zhou、Jian Sun
DOI:10.1016/j.tetlet.2009.09.097
日期:2009.12
A trimethylchlorosilane-promoted aza-Mannich reaction is reported utilizing enecarbamates as the nucleophile and aromatic N-Boc aldimines as the electrophile. A variety of nucleophiles and electrophiles are tolerated by the reaction conditions, delivering the adduct products in excellent yields with high E-stereoselectivities. (C) 2009 Elsevier Ltd. All rights reserved.