Nickel-Catalyzed Borylative Ring Opening of Vinyl Epoxides and Aziridines
摘要:
A mild ring opening of vinyl epoxides and aziridines with B(2)Pin(2) catalyzed by Ni(O)-Binap affords new functionalized allylic boron derivatives which undergo sequential transformations. The uncatalyzed allylation of aldehydes allows obtaining challenging bishomoallylic alicyclic 1,3-diols and 1,3-amino alcohols with remarkably high stereoselectivities. Valuable trans-bisallylic 1,4-amino alcohols can be obtained by a simple oxidation.
metal-catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose the cobalt-catalyzed hydroalkynylation of vinylaziridines giving rise to both linear and branched enynes. The optimization of the reaction conditions allowed to determine the key parameters of the cobalt-based catalytic system. The scope investigation
Catalyst-controlled divergent intermolecularcycloadditions of vinylaziridines with alkynes have been developed. By using [Rh(NBD)2]BF4 as the catalyst, a [3 + 2] cycloaddition reaction was achieved with broad substrate scope and high stereoselectivity under mild reaction conditions. Moreover, the chirality of vinylaziridines can be completely transferred to the [3 + 2] cycloadducts. When the catalyst
Diborylalkyllithium Salts Trigger Regioselective Ring Opening of Vinyl Aziridines
作者:Oriol Salvado、Riccardo Gava、Elena Fernández
DOI:10.1021/acs.orglett.9b03672
日期:2019.11.15
nucleophilic attack on vinyl aziridines with controlled regioselectivity. Preferred SN2 diborylalkylation ringopening reaction on the less sterically hindered position is observed with 1-tosyl-2-vinylaziridine, whereas exclusive SN2′ nucleophilic attack occurs on 2-methyl-1-tosyl-2-vinylaziridine. Cyclic vinyl aziridines interact through a third venue, via SN2 diborylalkylation ringopening reaction on the allylic
经LiTMP处理的gem -Diborylalkanes生成α-diborylalkane锂碱,该碱对区域的乙烯基氮丙啶进行亲核攻击,并具有可控的区域选择性。优选的小号Ñ就少的空间位阻的位置2 diborylalkylation开环反应与1-甲苯磺酰基-2- vinylaziridine观察到的,而排斥小号Ñ上2-甲基-1-对甲苯磺酰-2- vinylaziridine发生2'的亲核攻击。环状乙烯基氮丙啶经由烯丙基位置上的S N 2二硼烷基烷基化开环反应通过第三位点相互作用。在完全立体化学控制下形成均烯丙基二硼酸酯。
Selective [2+1] aziridination of conjugated dienes with a nitridomanganese complex: a new route to alkenylaziridines
nitridomanganese complex as a nitrogen source. The reaction proceeded selectively and in good yield via [2+1] addition to give alkenylaziridines, with no evidence for the formation of any [4+1] addition products. The first asymmetric version of the reaction was revealed in the aziridination of diene 5 with chiral complex 1.
Metal-Catalyzed (4 + 3) Cyclization of Vinyl Aziridines with <i>para</i>-Quinone Methide Derivatives
作者:Fei Jiang、Fu-Ru Yuan、Li-Wen Jin、Guang-Jian Mei、Feng Shi
DOI:10.1021/acscatal.8b03410
日期:2018.11.2
especially catalytic asymmetric versions, is needed in organic synthesis. This report describes an iridium-catalyzed (4 + 3) cyclization of vinyl aziridines with para-quinone methide (p-QM) derivatives, and this reaction constructs a seven-membered benzoxazepine scaffold in moderate to high yields (40% to 96%) and considerable diastereoselectivities (70:30 dr to >95:5 dr). Moreover, the catalytic asymmetric