1064138-56-2Relevant articles and documents
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.
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.
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.
