Chiral Selenide-Catalyzed Enantioselective Allylic Reaction and Intermolecular Difunctionalization of Alkenes: Efficient Construction of C-SCF₃ Stereogenic Molecules

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(14), С. 4782 - 4786

Опубликована: Март 27, 2018

New approaches for the synthesis of enantiopure trifluoromethylthiolated molecules by chiral selenide-catalyzed allylic trifluoromethylthiolation and intermolecular difunctionalization unactivated alkenes are disclosed. In these transformations, functional groups were well tolerated, desired products obtained in good yields with excellent chemo-, enantio-, diastereoselectivities. This reaction is nicely complementary to enantioselective trifluoromethylthiolation, functionalization, alkene difunctionalization.

Язык: Английский

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Enantioselective, Catalytic Vicinal Difluorination of Alkenes

Angewandte Chemie International Edition, Год журнала: 2018, Номер 57(50), С. 16431 - 16435

Опубликована: Сен. 26, 2018

Abstract The enantioselective, catalytic vicinal difluorination of alkenes is reported by I /I III catalysis using a novel, C 2 ‐symmetric resorcinol derivative. Catalyst turnover via in situ generation an ArI F species enabled Selectfluor oxidation and addition inexpensive HF–amine complex. HF:amine ratio employed this process provides handle for regioselective orthogonality as function Brønsted acidity. Selectivity reversal from the 1,1‐difluorination pathway (geminal) to desired 1,2‐difluorination (vicinal) disclosed (>20:1 both directions). Validation with electron deficient styrenes facilitates chiral bioisosteres venerable CF 3 unit that pervasive drug discovery (20 examples, up 94:06 e.r.). An achiral variant reaction also presented p ‐TolI (up >95 % yield).

Язык: Английский

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Oxidative Alkene Functionalizations via Selenium-π-Acid Catalysis

ACS Catalysis, Год журнала: 2017, Номер 7(9), С. 5828 - 5840

Опубликована: Авг. 8, 2017

Catalytic oxidative functionalizations of simple, nonpolarized alkenes represent one the lynchpin technologies in realm modern methodological chemical research. In this context, Lewis-acidic selenium species have experienced a steadily increasing scope applications catalytic oxidations simple throughout recent years. analogy to their metallic counterparts, such as cationic gold and platinum complexes, selenenium ions (i.e., RSe+) display an exceptional reactivity toward π-bonds, which allows for highly chemoselective electrophilic functionalization alkenes. This distinct profile enabled development diverse array bond-forming processes, allylic vinylic aminations, inter- intramolecular esterifications, halogenations, etherifications. Remarkable features associated with protocols are high regiocontrol, commonly mild reaction conditions, operational simplicity by selenium-catalyzed alkene can be conducted, exquisite functional group tolerance. These aspects make selenium-π-acid catalysis very attractive late-stage polyfunctionalized molecules, asset that still remains fully explored. Perspective, latest contributions field delineated placed into context indicatory insights gained from previous methodological, mechanistic, theoretical studies.

Язык: Английский

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Catalytic Enantioselective Dihalogenation in Total Synthesis

Accounts of Chemical Research, Год журнала: 2018, Номер 51(5), С. 1260 - 1271

Опубликована: Апрель 17, 2018

ConspectusTo date, more than 5000 biogenic halogenated molecules have been characterized. This number continues to increase as chemists explore chloride- and bromide-rich marine environments in search of novel bioactive natural products. Naturally occurring organohalogens span nearly all biosynthetic structural classes, exhibit a range unique biological activities, the subject numerous investigations. Despite abundance interest molecules, enantioselective methods capable forging carbon–halogen bonds synthetically relevant contexts remain scarce. Accordingly, syntheses often rely on multistep functional group interconversions establish stereocenters. Our has developed an dihalogenation reaction utilized it only reported examples catalytic halogenation product synthesis. In this Account, we describe our laboratory's development method for catalytic, application synthesis both mono- polyhalogenated first part, initial discovery TADDOL-mediated dibromination cinnamyl alcohols. Extension second-generation system selective bromochlorination, dichlorination, is then detailed. controlling enantioselectivity dihalide formation, chemoselectivity polyolefinic substrates, regioselectivity case bromochlorination. The ability exert control over halide delivery permits electronically nonbiased olefins required total synthesis.In second demonstrate how described provided efficient access host structurally diverse most direct methodology naturally vicinal dihalides. Chiral bromochlorides represent class >175 products; five members class, including its flagship member, (+)-halomon, accomplished through use Likewise, dichlorination two chlorosulfolipids, linear, acyclic polychlorides. Synthesis chiral monohalides achieved solvolysis enantioenriched bromochlorides; approach resulted bromocyclohexane-containing products enantiospecific bromopolyene cyclization. reviewing these syntheses, framework mediated by emerged.The highly enabling detail encourage further useful methodologies.

Язык: Английский

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Enantioselective Synthesis of Cyclobutenes by Intermolecular [2+2] Cycloaddition with Non-C₂ Symmetric Digold Catalysts

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(39), С. 13628 - 13631

Опубликована: Сен. 19, 2017

The enantioselective intermolecular gold(I)-catalyzed [2+2] cycloaddition of terminal alkynes and alkenes has been achieved using non-C

Язык: Английский

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Visible‐Light‐Induced Vicinal Dichlorination of Alkenes through LMCT Excitation of CuCl₂

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(52), С. 23603 - 23608

Опубликована: Сен. 14, 2020

Abstract This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis CuCl 2 in response to irradiation with visible light. catalysis proceeds via a ligand metal charge transfer process and provides an exciting opportunity for synthesis 1,2‐dichloride compounds using inexpensive, low‐molecular‐weight chlorine source. new exhibits wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions does not require external ligands. Mechanistic studies show that ready formation atom radicals is responsible facile C−Cl bonds this synthetic process.

Язык: Английский

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Catalytic Enantioselective Dihalogenation and the Selective Synthesis of (−)-Deschloromytilipin A and (−)-Danicalipin A

Journal of the American Chemical Society, Год журнала: 2016, Номер 138(15), С. 5150 - 5158

Опубликована: Март 28, 2016

A titanium-based catalytic enantioselective dichlorination of simple allylic alcohols is described. This reaction provides stereoselective access to all common dichloroalcohol building blocks used in syntheses chlorosulfolipid natural products. An synthesis ent-(-)-deschloromytilipin and a concise, eight-step ent-(-)-danicalipin are executed employ the as first step. Extension this system dibromination its use pentabromide stereoarrays relevant bromosulfolipids reported. The described reactions capable exerting diastereocontrol complex settings allowing X-ray crystal structure analysis unnatural diastereomers polyhalogenated stereohexads.

Язык: Английский

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Advances in Iodine(III)‐Mediated Halogenations: A Versatile Tool to Explore New Reactivities and Selectivities

Chemistry - A European Journal, Год журнала: 2016, Номер 22(26), С. 8728 - 8739

Опубликована: Апрель 8, 2016

Within the repertoire of organic chemical transformations, halogenation substrates is among most versatile, reliable, and broadly applicable reactions. Although a multitude different methods are known today, there still huge demand for novel and, in particular, catalytic that exhibit new reactivities selectivities. The class hypervalent iodanes meets exactly these needs thus offers great opportunity to fuel this highly desirable direction within field chemistry. This Concept gives short overview recent examples focusing on selective and/or mechanistically unusual halogenations.

Язык: Английский

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NXS, Morpholine, and HFIP: The Ideal Combination for Biomimetic Haliranium-Induced Polyene Cyclizations

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(12), С. 4344 - 4353

Опубликована: Фев. 7, 2018

In contrast to Nature that accomplishes polyene cyclizations seemingly with ease, such transformations are difficult conduct in the lab. our program dealing development of selective halogenations alkenes, we now asserted standard X+ reagents perfectly suited for biomimetic cation-π cyclization both electron rich and poor linear polyenes presence Lewis base morpholine acid HFIP. The method stands out due its broad substrate scope practicability together high chemical yields excellent selectivities, even highly challenging chloriranium-induced cyclizations.

Язык: Английский

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Catalytic, Vicinal Difluorination of Olefins: Creating a Hybrid, Chiral Bioisostere of the Trifluoromethyl and Ethyl Groups

ACS Catalysis, Год журнала: 2016, Номер 6(10), С. 7167 - 7173

Опубликована: Сен. 14, 2016

Contemporaneous reports describing the vicinal difluorination of olefins relying on I(I)/I(III) catalysis have augmented arsenal dihalogenation methods and provided a solution to this longstanding challenge in olefin functionalization. In both studies, success was contingent situ generation ArIF2 from simple aryl iodide, HF source, suitable terminal oxidant. The first report by Jacobsen co-workers employed resorcinol-derived iodide/m-CPBA oxidant combination, while laboratory relied p-iodotoluene Selectfluor. complementarity these approaches ensures that wide variety electronically distinct are viable substrates for transformation. This perspective describes our development catalytic as means efficiently construct hybrid, chiral bioisostere trifluoromethyl ethyl groups broader context molecular design highlights key other laboratories accelerated study.

Язык: Английский

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