Syntheses of 2-Benzylbenzofuran Derivatives and 2-Aryl-nitrochroman Derivatives from Nitroalkene Precursors
作者:Chia-Yu Huang、Chun-Wei Kuo、Veerababurao Kavala、Ching-Fa Yao
DOI:10.1002/ejoc.201600314
日期:2016.5
the synthesis of 2-benzylbenzofuran, 3-substituted 2-benzylbenzofuran, and 2-aryl-nitrochroman derivatives are described. Benzofurans were generated from nitroalkenes by reduction with NaBH4 followed by a Nef reaction and acid-mediated cyclization, whereas 3-substituted 2-benzylbenzofurans were prepared from nitroalkenes by reactions with Grignard reagents followed by a Nef reaction and an acid-mediated
Synthesis of Functionalized Arenopyrans and Arenylsulfanes via Reaction of Nitroallylic Acetates with Arenols and Arenethiols
作者:Pallabita Basu、Robi Sikdar、Tarun Kumar、Irishi N. N. Namboothiri
DOI:10.1002/ejoc.202000609
日期:2020.9.7
a furyl group which was synthesized in excellent yield (86 %, entry 1), dihydronaphthopyran 3b was synthesized in moderate yield by treating β‐naphthol 2a with appropriate MBH acetate 1b (entry 2). In the case of MBH acetates 1c–f, a reversal of regioselectivity leading to SN2 products 3' as the major or exclusive products was observed (entries 3–6). In the case of 1c and 1d, the minor SN2' products
我们注意到我们先前的手稿1中存在一些错误,并希望提供更正: 1.摘要第5行:“涉及S N 2'反应”应读为“涉及S N 2 / S N 2'反应” 2.第2页第2栏第2段:表2中的条目3–6的描述应为: 除了带有呋喃基的二氢萘并吡喃3a以极高的收率合成(86%,条目1)外,通过用适当的MBH乙酸酯1b处理β-萘酚2a也可以中等收率合成二氢萘并吡喃3b(条目2)。在MBH乙酸盐1c – f的情况下,观察到区域选择性的逆转,导致S N 2产物3'作为主要产物或排他产物(条目3–6)。在1c和1d的情况下,次要S N 2'乘积(<20%)3c和3d分别可以被隔离和表征(条目3-4)。 此外,表2中的反应和脚注已更新: 表2. MBH-乙酸盐范围aa 2-萘酚2a(0.36 mmol),MBH-乙酸酯1(0.4 mmol,1.1当量),NEt3(1.08 mmol,3当量)的DCM(6 mL)溶液。
Reduction of α,β-unsaturated nitroalkenes with borane and borohydrides. A convenient route to 3-nitro-, 3-hydroxylamino-, and 3-amino-2h-1-benzopyran derivatives
作者:Rajender S. Varma、Yuan-Zhu Gai、George W. Kabalka
DOI:10.1002/jhet.5570240343
日期:1987.5
The borohydride catalyzed boranereduction of 3-nitrochromenes provided a facile route to a variety of 3-hydroxylamino- 5 and 3-amino-2H-1-benzopyranes 6. Reduction with methoxyborohydride species, on the other hand, provided 3-nitrochromans 2,4.
硼氢化物催化的3-硝基苯并二氢硼烷还原为各种3-羟基羟氨基5和3-氨基-2 H -1-苯并吡喃提供了简便的途径。另一方面,用甲氧基硼氢化物还原可提供3-硝基苯并二氢吡喃2 ,4。