Regio- and stereoselective intramolecular hydroalkoxylation of aromatic alkynols: an access to dihydroisobenzofurans under transition-metal-free conditions
Synthesis of dibenzocyclohepta[1,2-<i>a</i>]naphthalene derivatives from phenylacetaldehyde and alkynyl benzyl alcohols <i>via</i> sequential electrophilic addition and double Friedel–Crafts reactions
作者:Archana K. Sahu、Ramanjaneyulu Unnava、Bipin K. Behera、Anil K. Saikia
DOI:10.1039/d1ob00057h
日期:——
been developed for the synthesis of substituted 9H-dibenzo[3,4:6,7]-cyclohepta[1,2-a]naphthalenes from phenylacetaldehydes and ortho-alkynyl benzyl alcohols in the presence of a Lewis acid in moderate to good yields within a short reaction time. Interestingly, the reaction proceeds through a highly regioselective electrophilic addition followed by double Friedel–Crafts reaction to form uncommon dibenzo-fused
已经开发了一种简单的方法,用于在路易斯酸存在下,由苯乙醛和邻炔基苄基醇合成取代的9 H-二苯并[3,4:6,7]-环庚[1,2- a ]萘。在较短的反应时间内中度到良好的收率。有趣的是,该反应是通过高度区域选择性的亲电加成反应进行的,然后进行两次Friedel-Crafts反应,形成不常见的二苯并稠合的七元碳环。
Efficient Synthesis of Isothiochromene Derivatives by Pd-Catalyzed Hydrothiolation Reaction
作者:Jie Feng、Meifang Lv、Guoping Lu、Chun Cai
DOI:10.1002/ejoc.201402611
日期:2014.8
An efficient method for the preparation of isothiochromenederivatives through the palladium-catalyzed intramolecular hydrothiolationreaction of halides and thiourea is reported. Two carbon–sulfur bonds are formed in this one-pot palladium-catalyzed cascade reaction. This new protocol is free from foul-smelling thiols and operates under mild conditions to give isothiochromenederivatives in excellent
Fused-Ring Formation by an Intramolecular “Cut-and-Sew” Reaction between Cyclobutanones and Alkynes
作者:Lin Deng、Likun Jin、Guangbin Dong
DOI:10.1002/anie.201712487
日期:2018.3.1
alkynes to construct cyclohexenone‐fused rings is described herein. The challenge arises from the need for selective coupling at the more sterically hindered proximal position, and can be addressed by using an electron‐rich, but less bulky, phosphine ligand. The control experiment and 13C‐labelling study suggest that the reaction may start with cleavage of the less hindered distal C−C bond of cyclobutanones
Catalytic silicon‐carbon or silicon‐heteroatom bond‐forming hydrosilylation has become increasingly important in synthetic chemistry, catalysis and organosilicon chemistry. Herein we report a platinum‐catalyzed one‐pot and tandem hydrosilylation/cyclization of OH‐containing alkynes with dihydrosilanes, allowing for facile synthesis of six‐membered organosiliconcompounds, including silyloxycycles and
efficient, regioselective Cu(OTf)2-catalyzed 5-exo-dig intramolecular hydroalkoxylation of 2-(ethynyl)benzyl alcohol, which provides a concise access to functionalized phthalan in high yields has been developed. A wide range of substrates possessing terminal, internal, and heteroaromatic alkynes can be efficiently transformed into the targeted phthalans. Substrates with primary, secondary, and tertiary benzyl