The Asymmetric Synthesis of Amines via Nickel-Catalyzed Enantioconvergent Substitution Reactions
作者:Ze-Peng Yang、Dylan J. Freas、Gregory C. Fu
DOI:10.1021/jacs.0c13034
日期:2021.2.24
dialkyl carbinamines do not provide general access to amines wherein the two alkyl groups are of similar size (e.g., CH2R versus CH2R1). Herein, we report two mild methods for the catalytic enantioconvergent synthesis of protected dialkyl carbinamines, both of which use a chiral nickel catalyst to couple an alkylzinc reagent (1.1–1.2 equiv) with a racemic partner, specifically, an α-phthalimido alkyl chloride
手性二烷基卡宾胺在有机化学、药物化学和生物化学等领域具有重要意义,例如用作生物活性分子、手性配体和手性催化剂。不幸的是,大多数用于合成二烷基卡宾胺的催化不对称方法不提供获得其中两个烷基具有相似大小的胺的一般途径(例如,CH 2 R与CH 2 R 1 )。在此,我们报道了两种催化对映异构合成受保护的二烷基卡宾胺的温和方法,这两种方法都使用手性镍催化剂将烷基锌试剂(1.1-1.2当量)与外消旋伙伴偶联,特别是α-邻苯二甲酰亚氨基烷基氯或受保护的 α-氨基酸的N-羟基邻苯二甲酰亚胺 (NHP) 酯。该方法用途广泛,可提供带有一系列官能团的二烷基卡宾胺衍生物。对于NHP酯的偶联,我们进一步描述了一种一锅变体,其中NHP酯原位生成,允许从市售氨基酸衍生物一步生成对映体富集的受保护的二烷基卡宾胺;我们通过将其应用于一系列有趣的目标分子的有效催化对映选择性合成来证明该方法的实用性。
Activation and synthetic applications of thiostannanes. Conversion of aldehydes and acetals into 1,3-dithianes with high chemodifferentiation
Novel method for transforming aldehydes and acetals into 1,3-dithianes has been achieved with the aid of organotin thioalkoxides and organotin triflates. Under these reaction conditions, various acid-sensitive groups are tolerated. Differentiation between aromatic or aliphatic aldehydes and acetals has been realized.
Regiospecific allylation of acetals with allylsilanes catalyzed by iodotrimethylsilane. Synthesis of homoallylethers
作者:Hideki Sakurai、Koshi Sasaki、Akira Hosomi
DOI:10.1016/0040-4039(81)80140-2
日期:1981.1
Allylation of acetals with allylsilanes is catalyzed by iodotrimethylsilane to give the corresponding homoallyl ethers, with regiospecific transposition of the allyl group.
缩醛与烯丙基硅烷的烯丙基化通过碘代三甲基硅烷催化,得到相应的均烯丙基醚,且烯丙基的区域特异性易位。
“ONE POT” DOUBLE CARBON–CARBON LINKAGES ON THE NEIGHBORING CARBONS VIA AN ENOL ETHER AS A REACTION INTERMEDIATE
Two new “one pot” double alkylation reactions, 1) allylation of α,β-enones with allylsilanes and subsequent reaction with electrophiles, and 2) acylation of α-siloxyallylsilanes with acid halides followed by consecutive introduction of other electrophiles on the neighboring carbon atom, are reported.