Carbohydrates as chiral templates: diastereoselective synthesis of N-glycosyl-N-homoallylamines and .beta.-amino acids from imines
摘要:
Complexing properties and chirality of carbohydrates were utilized in diastereoselective reactions of O-pivaloylated N-galactosylimines with allylsilanes and -stannanes. With allyltrimethylsilane in the presence of SnCl4, imines 2 of aromatic and heteroaromatic aldehydes were converted to homoallylamines 3, giving ratios of diastereomers higher than 7:1. No addition products derived from alpha-anomeric aromatic imines were formed. Aliphatic homoallylamines 3 were synthesized by using allyltributylstannane in the presence of SnCl4. Both alpha- and beta-anomeric aliphatic imines reacted with the allylstannane. They gave the same ratio of diastereomers and showed the same sense of asymmetric induction.
New enolate-carbodiimide rearrangement in the concise synthesis of 6-amino-2,3-dihydro-4-pyridinones from homoallylamines
作者:N. Yu. Kuznetsov、R. M. Tikhov、I. A. Godovikov、V. N. Khrustalev、Yu. N. Bubnov
DOI:10.1039/c6ob00293e
日期:——
Three-step synthesis of 6-amino-2,3-dihydro-4-pyridinones from homoallylamines involving NBS (or I2, PhSeCl)-mediated cyclization of N-(3-butenyl)ureas to 6-(bromomethyl)-2-iminourethanes, dehydrohalogenation and the novel enolate-carbodiimide rearrangement as a key step has been developed. The...
A New Method of Synthesis of 6-Substituted Piperidine-2,4-diones from Homoallylamines
作者:Nikolai Yu. Kuznetsov、Victor I. Maleev、Victor N. Khrustalev、Anna F. Mkrtchyan、Ivan A. Godovikov、Tatyana V. Strelkova、Yuri N. Bubnov
DOI:10.1002/ejoc.201101114
日期:2012.1
triallylborane and enantiomerically enriched N-Boc-1-phenyl-3-butenylamine was synthesized by the addition of (–)-AllB(Ipc)2 to the corresponding silylimine. Chiral precursors containing a carboxylic ester group were synthesized from (S)-allylglycine and-alanine. The reactions of N-Boc derivatives with NBS smoothly produced the corresponding bromocyclocarbamates either in the form of a single diastereomer or
Studies directed toward the synthesis of viridenomycin. Route 1: assembly of three advanced intermediates
作者:Albert W Kruger、A.I Meyers
DOI:10.1016/s0040-4039(01)00700-6
日期:2001.6
Three enantiomerically and geometrically pure building blocks representing fragments of the antifungal antibiotic viridenomycin have been prepared.
已经制备了代表抗真菌抗生素viridenomycin片段的三个对映异构体和几何纯净的结构单元。
Amine adducts of triallylborane as highly reactive allylborating agents for Cu(i)-catalyzed allylation of chiral sulfinylimines
作者:Michael S. Alexeev、Tatiana V. Strelkova、Michael M. Ilyin、Yulia V. Nelyubina、Ivan A. Bespalov、Michael G. Medvedev、Victor N. Khrustalev、Nikolai Yu. Kuznetsov
DOI:10.1039/d4ob00291a
日期:——
active reagents is an attractive strategy that meets the modern principles of sustainable development of chemistry. In the current study, we for the first time describe the method and general principles of Cu(I)-catalyzed allylation of imines with amine adducts of allylic triorganoboranes. Triallylborane is an extremely reactive compound and cannot be used for the catalytic allylation of imines, whereas
使用高活性试剂实施选择性催化过程是一种有吸引力的策略,符合化学可持续发展的现代原则。在本研究中,我们首次描述了Cu( I )催化亚胺与烯丙基三有机硼烷胺加合物的烯丙基化反应的方法和一般原理。三烯丙基硼烷是一种极其活泼的化合物,不能用于亚胺的催化烯丙基化,而其胺加合物是理想的催化底物。胺片段的结构成功地平衡了烯丙基硼试剂的安全性、选择性和稳定性,使其在催化烯丙基化反应中表现出高活性,超过任何已知的烯丙基硼烷许多倍。获得的结果得到定量动力学数据和 DFT 计算的支持。该系统的催化功效在亚磺酰亚胺模型(23 个例子)上得到了证明。实现了高达 >99% 的高非对映选择性,包括克级合成 2-羟基苯基衍生物。考虑到三烯基硼烷(AAT)的胺加合物的高反应活性和无与伦比的原子经济性,它们可以被认为是Cu( I )和其他合适金属催化剂的潜在烯丙基化试剂。
(−)-Sparteine-Mediated α-Lithiation of <i>N</i>-Boc-<i>N</i>-(<i>p</i>-methoxyphenyl)benzylamine: Enantioselective Syntheses of (<i>S</i>) and (<i>R</i>) Mono- and Disubstituted <i>N</i>-Boc-benzylamines