ABSTRACT
We present here the distal-C-H activation/functionalization of biphenyl scaffolds using aliphatic nitrile templates. The approach has demonstrated good to exclusive meta selectivities over a wide range of olefination and acetoxylation substrates. In addition, bis-olefination has been accomplished in a one-pot, sequential manner. Notably, this technique highlights the diversification of pharmaceuticals and natural products. Consequently, the temporary directing aliphatic template has been recovered quantitively from the coupled product.
ABSTRACT
Herein, we report the meta-C-H olefination of arylmethanesulfonates aided by a potentially versatile aliphatic nitrile-directing group under microwave irradiation conditions with fair to very good yields and good to outstanding regioselectivities. Significantly, the protocol showed broad substrate scope including olefin-derived drugs and cyclic olefins. Remarkably, a dual meta-C-H bond was amenable to generating the bis-olefination products.
ABSTRACT
Herein, we report the first microwave-assisted remote-C-H functionalization aided by a simple nitrile directing template. Notably, the present protocol showed a broad substrate scope VIA enabling meta-C-H arylation, acetoxylation, and cyanation. Significantly, the microwave-accelerated meta-C-H functionalization was effective with short reaction times without compromising yields and site selectivity. In addition, ibuprofen drug diversification was accomplished by carrying out arylation, acetoxylation, and cyanation. Importantly, meta-dual-hetero functionalization has been presented.
ABSTRACT
This article describes the development of a new aliphatic nitrile-template-directed remote meta-selective C-H olefin functionalization reaction of arenes. Remarkably, unlike the previous reports, this process is feasible at room temperature and enabled the formation of products with excellent regioselectivity. The present protocol encompasses a broad spectrum of substituted dihydrocinnamic acids and olefins, producing meta-C-H olefinated products (up to 96% yield). In addition, the efficacy of the present method has been showcased by the synthesis of various drug analogues (e.g., cholesterol, estrone, ibuprofen, and naproxen). Significantly, the robustness of meta-olefination was also demonstrated by gram-scale synthesis. The new nitrile-based meta-directing template, in particular, could be easily synthesized in two steps and recycled under mild conditions.
Subject(s)
Alkenes , Nitriles , Catalysis , TemperatureABSTRACT
Herein, we present m-C-H olefination on derivatives of phenylacetic acids by tethering with a simple nitrile-based template through palladium catalysis. Notably, the versatility of the method is evaluated with a wide range of phenylacetic acid derivatives for obtaining the meta-olefination products in fair to excellent yields with outstanding selectivities under mild conditions. Significantly, the present strategy is successfully exemplified for the synthesis of drugs/natural product analogues (naproxen, ibuprofen, paracetamol, and cholesterol).
ABSTRACT
Recent research has been focused on the transition metal-catalyzed reactions. Herein we have developed nickel-catalyzed synthesis of 3-aryl benzofurans from ortho-alkenyl phenols via intramolecular dehydrogenative coupling. Notably, simple O2 gas served as an oxidant, without using any sacrificial hydrogen acceptor. The strategy enabled the synthesis of 3-aryl benzofurans in good to excellent yields.
