1064138-56-2Relevant academic research and scientific papers
Diastereoselectively Complementary C-H Functionalization Enables Access to Structurally and Stereochemically Diverse 2,6-Substituted Piperidines
Wang, Gang,Mao, Ying,Liu, Lei
, p. 6476 - 6479 (2016)
The preparation of 2,6-substituted piperidine derivatives through diastereoselective C-H functionalization of corresponding nitrogen heterocycles represents an appealing protocol and yet remains a formidable challenge. Here, we describe a stereochemically complementary oxidative C-H functionalization of N-carbamoyl tetrahydropyridines with a wide variety of building blocks, providing either the cis- or trans-2,6-substituted piperidines with diverse patterns of functionalities. The mild metal-free process exhibits excellent regio- and diastereoselectivities as well as functional group tolerance. The synthetic utilities in natural product and analogue syntheses are also described.
Synthesis of Benzylic Alcohols by C-H Oxidation
Tanwar, Lalita,B?rgel, Jonas,Ritter, Tobias
supporting information, p. 17983 - 17988 (2019/11/14)
Selective methylene C-H oxidation for the synthesis of alcohols with a broad scope and functional group tolerance is challenging due to the high proclivity for further oxidation of alcohols to ketones. Here, we report the selective synthesis of benzylic alcohols employing bis(methanesulfonyl) peroxide as an oxidant. We attempt to provide a rationale for the selectivity for monooxygenation, which is distinct from previous work; a proton-coupled electron transfer mechanism (PCET) may account for the difference in reactivity. We envision that our method will be useful for applications in the discovery of drugs and agrochemicals.
Nickel/bis(oxazoline)-catalyzed asymmetric negishi arylations of racemic secondary benzylic electrophiles to generate enantioenriched 1,1-diarylalkanes
Do, Hien-Quang,Chandrashekar,Fu, Gregory C.
supporting information, p. 16288 - 16291 (2013/12/04)
A tertiary stereogenic center that bears two different aryl substituents is found in a variety of bioactive compounds, including medicines such as Zoloft and Detrol. We have developed an efficient method for the synthesis of enantioenriched 1,1-diarylalkanes from readily available racemic benzylic alcohols. Formation of a benzylic mesylate (which is not isolated), followed by treatment with an arylzinc reagent, LiI, and a chiral nickel/bis(oxazoline) catalyst, furnishes the Negishi cross-coupling product in high ee and good yield. A wide array of functional groups (e.g., an aryl iodide, a thiophene, and an N-Boc-indole) are compatible with the mild reaction conditions. This method has been applied to a gram-scale synthesis of a precursor to Zoloft.
Hydroformylation of homoallylic azides: A rapid approach toward alkaloids
Spangenberg, Thomas,Breit, Bernhard,Mann, Andre
supporting information; experimental part, p. 261 - 264 (2009/08/08)
(Chemical Equation Presented) Unprecedented hydroformylation of homoallylic azides combined with useful one-pot operations provides an expeditive access to alkaloids.
Stereoselective synthesis of cis- or trans-3,5-disubstituted pyrazolidines via pd-catalyzed carboamination reactions: Use of allylic strain to control product stereochemistry through N-substituent manipulation
Giampietro, Natalie C.,Wolfe, John P.
supporting information; experimental part, p. 12907 - 12911 (2009/03/12)
The stereoselective synthesis of either trans- or cis-3,5-disubstituted pyrazolidines is accomplished via Pd-catalyzed carboamination reactions of unsaturated hydrazine derivatives. The products are obtained in good yield with up to >20:1 diastereoselectivity. Stereocontrol is achieved by modulating the degree of allylic strain in the transition state for syn-aminopalladation through a simple modification of the substrate N2-substituent. The pyrazolidine products can be further transformed to 3,5-disubstituted pyrazolines via deprotection/oxidation, or to substituted 1,3-diamines via N-N bond cleavage.
