Results 81 to 90 of about 3,998 (209)

Synthesis of Functionalized Tetrahydropyridines by SNCl4-mediated [4+2] Cycloaddition between Donor–Acceptor Cyclobutanes and Nitriles [PDF]

, 2019
Cycloadditions of strained carbocycles promoted by Lewis acids are powerful methods to construct heterocyclic frameworks. In fact, the formal [3+2] cycloadditions of donor-acceptor (DA) cyclopropanes with nitriles has seen particular success in synthesis.
Bazinski, Nathan, Koo, Donghyun, Pagenkopf, Brian, Tong, David, Vemula, Naresh, Wu, Jackie   +5 more
core   +2 more sources

Constitutive nitric oxide synthases deficiency impairs cyclobutane pyrimidine dimer repair following solar UV exposure in cells and mice

Photochemistry and Photobiology, EarlyView.
Proposed model for the dual role of cNOS in DNA damage and repair upon UV radiation. Abstract Solar ultraviolet (sUV) radiation is a major environmental factor that induces DNA damage, promoting skin aging and carcinogenesis. The formation of cyclobutane pyrimidine dimers (CPDs) is one of the most prevalent forms of UV‐induced DNA lesions, playing a ...
Veronica Bahamondes Lorca, Yuxi Zhou, Christina Athans, Hailey Payne, Madison Wright, Zeinab Feyyaz, Lingying Tong, Dawn L. Sammons, Shiyong Wu   +8 more
wiley   +1 more source

BODIPY-Labeled Cyclobutanes by Secondary C(sp3)─H Arylations for Live-Cell Imaging [PDF]

, 2019
Arylated cyclobutanes were accessed by a versatile palladium‐catalyzed secondary C(sp 3 )−H activation, exploiting chelation assistance by modular triazoles.
Ackermann, Lutz, Fernandez Vargas, Antonio, Kuniyil, Rositha, Scott, Jamie, Vendrell Escobar, Marc, Virelli, Matteo, Wang, Wei, Wu, Jun, Zanoni, Giuseppe   +8 more
core   +1 more source

Investigation of 222‐nm ultraviolet C irradiation bactericidal effect on the surgical field in a rabbit model

Photochemistry and Photobiology, EarlyView.
In a rabbit surgical field model seeded with polymicrobial flora, a single dose of 222‐nm UV‐C (500 mJ/cm2) markedly reduced bacterial colonies, achieving a bactericidal effect comparable to 254‐nm UV‐C (200 mJ/cm2), while no UV‐C irradiation showed heavy growth. Wound healing did not differ among groups. Microbiota profiling detected SSI‐relevant taxa
Tomoaki Fukui, Yuya Yamamoto, Kyohei Takase, Keisuke Oe, Kenichi Sawauchi, Ryota Nishida, Takahiro Niikura, Rena Kaigome, Masahiro Sasaki, Toru Koi, Hiroyuki Ohashi, Ryosuke Kuroda   +11 more
wiley   +1 more source

A comparison of the benzylic and the allylic group as a donor in the formal [4+2] cycloaddition to tetrahydropyrans using donor-acceptor cyclobutanes [PDF]

, 2017
The allyl group was shown to be preferred over the benzyl group as a donor in the formal [4+2]-cycloaddition reaction between a donor-acceptor cyclobutane and various aldehydes to give ...
Awais Ahmed (2570458), Gareth Pritchard (1249743), Steven Christie (1256589)   +2 more
core   +1 more source

Direct evidence of singlet molecular oxygen [O2 (1Δg)] production from UVA excited 6‐thioguanine

Photochemistry and Photobiology, EarlyView.
6‐Thioguanine (6‐TGua) is incorporated into DNA as a purine analogue, inhibiting cell replication. Patients treated with 6‐TGua are more prone to developing skin cancer due to the photoexcitation of 6‐TGua by UVA radiation (as illustrated in the Jablonski diagram). Upon exposure to UVA, the excited 6‐TGua generates 1O2.
André L. Lopes, Fernanda M. Prado, Helena C. Junqueira, Marisa H. G. Medeiros, Graziella E Ronsein, Jean Cadet, Paolo Di Mascio   +6 more
wiley   +1 more source

The Total Synthesis of (–)-Scabrolide A [PDF]

, 2020
The first total synthesis of the norcembranoid diterpenoid scabrolide A is disclosed. The route begins with the synthesis of two chiral pool-derived fragments, which undergo a convergent coupling to expediently introduce all 19 carbon atoms of the ...
Hafeman, Nicholas J., Loskot, Steven A., Pritchett, Beau P., Reimann, Christopher E., Stoltz, Brian M., Virgil, Scott C.   +5 more
core  

Ytterbium triflate catalyzed synthesis of alkoxy-substituted donor-acceptor cyclobutanes and their formal [4 + 2] cycloaddition with imines: stereoselective synthesis of piperidines. [PDF]

, 2010
A new synthesis of 2-alkoxy-1,1-cyclobutane diesters and their first use in dipolar cycloadditions is reported. Both the formation of the donor-acceptor cyclobutanes and their subsequent annulation with in situ formed imines are catalyzed by Yb(OTf)(3 ...
Moustafa, Mahmoud M Abd Rabo, Pagenkopf, Brian L   +1 more
core   +3 more sources

RAD51 and RAD51 paralog inhibition sensitizes nonreplicating quiescent keratinocytes to UV radiation

Photochemistry and Photobiology, EarlyView.
UV radiation and other compounds generate DNA adducts that block transcription and induce cell death if not removed by the nucleotide excision repair system. In this work, we used a small‐scale pharmacological screen to discover that inhibition of the recombinase RAD51 sensitized nonreplicating quiescent keratinocytes to both UVR and other agents that ...
Saman Khan, Angitha Nair, M. Alexandra Carpenter, Michael G. Kemp   +3 more
wiley   +1 more source

The concept of Gallium-controlled double C–H functionalization of aliphatic CH2-groups driven by Vinyl carbocations

Nature Communications
The direct C–H activation of inert C(sp3)–H bonds in a hydrocarbon chain has been a very attractive target in organic synthesis for many decades. Among all the variety of processes, those driven by vinyl carbocations are quite scarce thus far, and it is ...
Roman A. Novikov, Denis D. Borisov, Dmitry A. Denisov, Maxim A. Novikov, Konstantin V. Potapov, Yaroslav V. Tkachev, Yury V. Tomilov   +6 more
doaj   +1 more source