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1. Acceptor Influence on Thiolate Sensing by Hemicyanine Dyes

Author:
Chung, Andrew J.; Deore, Prashant S.; Al-Abdul-Wahid, Sameer; Aboelnga, Mohamed M.; Wetmore, Stacey D.; Manderville, Richard A.
Source:
Journal of organic chemistry 2019 v.84 no.4 pp. 2261-2268
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; Lewis acids; Lewis bases; chemical reactions; dyes; enamines; gases; moieties; nitrogen; nuclear magnetic resonance spectroscopy; organic chemistry; sodium hydroxide; thermodynamics;     Show all 13 Subjects
Abstract:
... Promoting selective interactions between a nucleophile and electrophilic dye in complex environments is a central goal in nucleophilic chemosensor development. Commonly employed dyes are hemicyanines containing either the N-methylbenzothiazolium (Btz) or the N-methyl-3,3-dimethylindolium (Ind) acceptors. The dyes are related to α,β-unsaturated carbonyls and contain two sites of reactivity (C₂ vs C ...
DOI:
10.1021/acs.joc.9b00066

2. A Computational Study on the Stereo- and Regioselective Formation of the C4α–C6′ Bond of Tethered Catechin Moieties by an Exhaustive Search of the Transition States

Author:
Fukaya, Keisuke; Saito, Akiko; Nakajima, Noriyuki; Urabe, Daisuke
Source:
Journal of organic chemistry 2019 v.84 no.5 pp. 2840-2849
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; catechin; chemical reactions; geometry; hydrogen bonding; mechanics; models; moieties; organic chemistry; procyanidins;     Show all 10 Subjects
Abstract:
... We previously reported the total synthesis of procyanidin B6 by using the stereo- and regioselective C–C bond formation of tethered catechin moieties as the key step. The reaction afforded the product bearing a new C4α–C6′ bond linkage instead of the inherently preferable C4α–C8′ bond. However, the origin of this selectivity remained unclear due to the complex structure of the substrate. Here we r ...
DOI:
10.1021/acs.joc.8b03263

3. Addition of α-Cyanomethylpyridine to Naphthalimide via Trifluoromethyl-Directed CH Functionalization: Cyanide Sensing in Aqueous Media

Author:
Li, Zheyao; Rao, Caihui; Chen, Lu; Fu, Chao; Zhu, Tingting; Chen, Xi; Liu, Chuanxiang
Source:
Journal of organic chemistry 2019 v.84 no.11 pp. 7518-7522
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; bromine; chemical bonding; chemical structure; colorimetry; cyanides; fluorescent dyes; isomerization; nitriles; organic chemistry; receptors;     Show all 11 Subjects
Abstract:
... A colorimetric anion sensor based on the activated C–H group is described, and the selective and reusable detection of cyanide using the sensor is demonstrated. The system uses bromine to block isomerization and trifluoromethyl-directed C–H regioselective functionalization for direct C–C bond formation between a fluorophore and 2-(pyridin-2-yl)acetonitrile. Thus, this system provides a new way to ...
DOI:
10.1021/acs.joc.9b00904

4. β-AlkenylBODIPY Dyes: Regioselective Synthesis via Oxidative C–H Olefination, Photophysical Properties, and Bioimaging Studies

Author:
Wang, Jun; Li, Yongxin; Gong, Qingbao; Wang, Hua; Hao, Erhong; Lo, Pui-Chi; Jiao, Lijuan
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5078-5090
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; Lewis bases; amines; chemical reactions; chemical structure; dyes; fluorescence; organic chemistry; stereoselectivity;     Show all 9 Subjects
Abstract:
... A series of 2-alkenyl- and 2,6-dialkenylboron dipyrromethene (BODIPY) derivatives were synthesized through Pd(II)-catalyzed regioselective and stereoselective oxidative C–H olefination in one step. The 2-alkenyl BODIPY derivative further reacted with various amines regioselectively at the 5-position through direct oxidative nucleophilic substitution. The photophysical properties of the 2-alkenyl- ...
DOI:
10.1021/acs.joc.9b00020

5. Amination of Carbenium Ions Generated by Directed Protonolysis of Cyclopropane

Author:
Skvorcova, Marija; Lukasevics, Lukass T.; Jirgensons, Aigars
Source:
Journal of organic chemistry 2019 v.84 no.7 pp. 3780-3792
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; amination; carboxamides; chemical bonding; chemical structure; ions; nitriles; organic chemistry; urea;     Show all 9 Subjects
Abstract:
... Directed intramolecular protonolyis of the cyclopropane C–C bond is demonstrated as a strategy to generate carbenium ions. This intermediate can be subjected to amination with nitriles under Ritter reaction conditions. Directing groups such as carbamate, carboxamide, urea, ester, and ketone were found to be efficient for regioselective anti-Markovnikov cleavage of cyclopropane. Depending on the di ...
DOI:
10.1021/acs.joc.8b02576

6. A New Member of the BN-Phenanthrene Family: Understanding the Role of the B—N Bond Position

Author:
Abengózar, Alberto; Sucunza, David; García-García, Patricia; Sampedro, Diego; Pérez-Redondo, Adrián; Vaquero, Juan J.
Source:
Journal of organic chemistry 2019 v.84 no.11 pp. 7113-7122
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; bromine; chemical bonding; chemical reactions; chemical structure; computational methodology; fluorescence; optical properties; organic chemistry; organic compounds;     Show all 10 Subjects
Abstract:
... 3,4-Dihydro-4-aza-3-boraphenanthrene, which shows the highest fluorescence quantum yield of all nonsubstituted BN-phenanthrenes reported to date (ϕF = 0.61), has been synthesized in only three steps (76% overall yield) from easily accessible 1-bromo-2-vinylnaphthalene, along with several substituted derivatives. The reactivity of these previously unknown BN-aromatic compounds toward organolithium ...
DOI:
10.1021/acs.joc.9b00800

7. Application of the Suzuki–Miyaura Reaction for the Postfunctionalization of the Benzo[4,5]thiazolo[3,2-c][1,3,5,2]oxadiazaborinine Core: An Approach toward Fluorescent Dyes

Author:
Potopnyk, Mykhaylo A.; Volyniuk, Dmytro; Luboradzki, Roman; Ceborska, Magdalena; Hladka, Iryna; Danyliv, Yan; Gražulevičius, Juozas Vidas
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5614-5626
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; Suzuki reaction; acids; boron; catalytic activity; fluorescence; fluorescent dyes; moieties; organic chemistry; organic compounds; palladium; solvents;     Show all 12 Subjects
Abstract:
... A fluorescent dye based on the 8-brominated benzo[4,5]thiazolo[3,2-c][1,3,5,2]oxadiazaborinine core was synthesized from benzo[d]thiazol-2-amine. The new boron complex can be effectively modified by a palladium-catalyzed Suzuki–Miyaura cross-coupling reaction with (het)arylboronic acids. This reaction allows a valuable regioselective postfunctionalization of 1,3,5,2-oxadiazaborinine chromophores w ...
DOI:
10.1021/acs.joc.9b00566

8. Biomimetic Enantioselective Total Synthesis of (−)-Robustanoids A and B and Analogues

Author:
Liu, Zhan-Jiang; Huang, Pei-Qiang
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5627-5634
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; biomimetics; biosynthesis; chemical structure; cyclization reactions; enantioselectivity; organic chemistry; organic compounds;     Show all 8 Subjects
Abstract:
... We report a step-economical, enantioselective total synthesis of (−)-robustanoid B and (−)-robustanoid A and four novel natural product-like compounds. Our strategy relied on our biosynthetic hypothesis and on a novel complexity generation methodology, namely, the one-pot hydroxylative double cyclization reaction. The latter consists of a modified 3,3-dimethyldioxirane-triggered epoxidation—epoxid ...
DOI:
10.1021/acs.joc.9b00573

9. Bonded to Carbon or Nitrogen? This is a Question on the Regioselectivity in Hyperconjugative Aromaticity

Author:
Sun, Tingting; Guo, Ping; Xie, Qiong; Zhao, Liang; Zhu, Jun
Source:
Journal of organic chemistry 2019 v.84 no.7 pp. 3881-3886
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; aromatic compounds; carbon; chemical reactions; dissociation; energy; isomers; nitrogen; organic chemistry; prediction; thermodynamics;     Show all 11 Subjects
Abstract:
... In chemistry, regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions. Although it has been extensively investigated in various reactions, the regioselectivity of hyperconjugative aromaticity on either main group systems or transition metal ones remains elusive due to the challenge of synthesizing the target products. Here we repor ...
DOI:
10.1021/acs.joc.8b02996

10. Chemo- and Regioselective Asymmetric Synthesis of Cyclic Enamides through the Catalytic Umpolung Organocascade Reaction of α-Imino Amides

Author:
Yoshida, Yasushi; Hiroshige, Tomohiko; Omori, Kazuki; Mino, Takashi; Sakamoto, Masami
Source:
Journal of organic chemistry 2019 v.84 no.11 pp. 7362-7371
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; amides; chemical reactions; enantiomers; enantioselectivity; organic chemistry; stereoselective synthesis;     Show all 7 Subjects
Abstract:
... The efficient chemo- and regioselective catalytic asymmetric syntheses of enamides, which are important core structures of bioactive natural products, have been achieved through the first umpolung organocascade reaction of α-imino amides. A variety of enamides have been synthesized enantioselectively in high yields with up to 99% ee. Notably, both enantiomers of the products can be selectively pre ...
DOI:
10.1021/acs.joc.9b01036

11. Chiral Bidentate Boryl Ligand Enabled Iridium-Catalyzed Asymmetric C(sp²)–H Borylation of Diarylmethylamines

Author:
Zou, Xiaoliang; Zhao, Haonan; Li, Yinwu; Gao, Qian; Ke, Zhuofeng; Senmiao Xu,
Source:
Journal of the American Chemical Society 2019 v.141 no.13 pp. 5334-5342
ISSN:
1520-5126
Subject:
regioselectivity,   etc   ; acids; catalytic activity; chemical bonding; enantioselectivity; ligands; organic chemistry;     Show all 7 Subjects
Abstract:
... Optically active organoboronic acids and their derivatives are an important family of target compounds in organic chemistry, catalysis, and medicinal chemistry. Yet there are rare asymmetric catalytic examples reported for the synthesis of these compounds via atom and step economic ways. Herein, we report a chelate-directed iridium-catalyzed asymmetric C(sp²)–H borylation of aromatic C–H bonds dir ...
DOI:
10.1021/jacs.8b13756

12. Construction of 5-Aminotetrazoles via in Situ Generation of Carbodiimidium Ions from Ketones Promoted by TMSN₃/TfOH

Author:
Nimnual, Phongprapan; Tummatorn, Jumreang; Boekfa, Bundet; Thongsornkleeb, Charnsak; Ruchirawat, Somsak; Piyachat, Pawida; Punjajom, Kunlayanee
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5603-5613
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; chemical reactions; chemical structure; density functional theory; ions; ketones; organic chemistry;     Show all 7 Subjects
Abstract:
... A novel synthetic approach for the synthesis of 5-aminotetrazoles has been developed by employing simple ketones as substrates. This methodology involved the N₂-extrusion/aryl migration of azido complexes as the key step for the in situ generation of carbodiimidium ion, which could further react with hydrazoic acid and cyclize intramolecularly to provide 5-aminotetrazoles in good to excellent yiel ...
DOI:
10.1021/acs.joc.9b00555

13. Copper-Catalyzed Asymmetric Hydroboration of 2H-Chromenes Using a Chiral Diphosphine Ligand

Author:
Li, Xiufen; Wang, Chaoqiong; Song, Jianqiao; Yang, Zhihong; Zi, Guofu; Hou, Guohua
Source:
Journal of organic chemistry 2019 v.84 no.13 pp. 8638-8645
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; catalytic activity; chemical reactions; chemical structure; enantioselectivity; ligands; organic chemistry; organic compounds;     Show all 8 Subjects
Abstract:
... A highly regioselective asymmetric hydroboration of 2H-chromenes catalyzed by the complex of CuCl and diphosphine ligand (S,R)-DuanPhos has been realized under mild conditions to produce 3-boryl chromans, achieving good yields and excellent enantioselectivities up to 96% ee. This work provides an efficient approach to the synthesis of chiral 3-boryl chromans and derivatives. ...
DOI:
10.1021/acs.joc.9b01109

14. Copper-Catalyzed Radical C–C Bond Cleavage and [4+1] Annulation Cascade of Cycloketone Oxime Esters with Enaminothiones

Author:
He, Yuan; Lou, Jiang; Wu, Kaikai; Wang, Hongmei; Yu, Zhengkun
Source:
Journal of organic chemistry 2019 v.84 no.4 pp. 2178-2190
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; catalytic activity; chemical bonding; chemical reactions; chemical structure; cleavage (chemistry); copper; esters; organic chemistry; thermodynamics;     Show all 10 Subjects
Abstract:
... Carbon–carbon bond formation is among the most important reactions in organic synthesis. Reconstruction of a carbon–carbon bond through ring-opening C–C bond cleavage of a strained carbocycle usually occurs via a thermodynamically preferable pathway. However, carbon–carbon bond formation through thermodynamically less favorable C–C bond cleavage has seldom been documented. Herein, we disclose an u ...
DOI:
10.1021/acs.joc.8b03175

15. Cp*Coᴵᴵᴵ–Catalyzed Alkylation of Primary and Secondary C(sp³)-H Bonds of 8-Alkylquinolines with Maleimides

Author:
Kumar, Rakesh; Kumar, Rohit; Chandra, Devesh; Sharma, Upendra
Source:
Journal of organic chemistry 2019 v.84 no.3 pp. 1542-1552
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; alkylation; cobalt; moieties; organic chemistry; quinoline;     Show all 6 Subjects
Abstract:
... The cobalt(III)-catalyzed C(sp³)-H bond alkylation of 8-methyl quinoline with maleimides is reported. In contrast to the rhodium-catalyzed method, in the current cobalt-catalyzed method, a catalytic amount of acid is used, and importantly, it is also applicable to secondary C(sp³)-H bond alkylation. The developed methodology is applicable for N-alkyl- and N-aryl-substituted maleimides and unsubsti ...
DOI:
10.1021/acs.joc.8b02974

16. CuH-Catalyzed Enantioselective Alkylation of Indole Derivatives with Ligand-Controlled Regiodivergence

Author:
Ye, Yuxuan; Kim, Seoung-Tae; Jeong, Jinhoon; Baik, Mu-Hyun; Buchwald, Stephen L.
Source:
Journal of the American Chemical Society 2019 v.141 no.9 pp. 3901-3909
ISSN:
1520-5126
Subject:
regioselectivity,   etc   ; Lewis acids; Lewis bases; alkylation; catalysts; copper; density functional theory; enantioselectivity; hydrides; indoles; ligands; organic chemistry;     Show all 12 Subjects
Abstract:
... Enantioenriched molecules bearing indole-substituted stereocenters form a class of privileged compounds in biological, medicinal, and organic chemistry. Thus, the development of methods for asymmetric indole alkylation is highly valuable in organic synthesis. Traditionally, achieving N-selectivity in indole alkylation reactions is a significant challenge, since there is an intrinsic preference for ...
DOI:
10.1021/jacs.8b11838

17. [3 + 2] Cycloaddition of para-Quinone Methides with Nitrile Imines: Approach to Spiro-pyrazoline-cyclohexadienones

Author:
Su, Yingpeng; Zhao, Yanan; Chang, Bingbing; Zhao, Xiaolong; Zhang, Rong; Liu, Xuan; Huang, Danfeng; Wang, Ke-Hu; Huo, Congde; Hu, Yulai
Source:
Journal of organic chemistry 2019 v.84 no.11 pp. 6719-6728
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; cycloaddition reactions; imines; moieties; organic chemistry; quinones;     Show all 6 Subjects
Abstract:
... [3 + 2] cycloaddition of para-quinone methides with nitrile imines under mild conditions has been achieved. The corresponding spiro-pyrazoline-cyclohexadienone products were constructed in good to excellent yields (up to 97% yield) with high regioselectivity. This straightforward protocol exhibits good functional group tolerance and scalability and provides the spiro-pyrazoline-cyclohexadienones. ...
DOI:
10.1021/acs.joc.9b00434

18. [4 + 2] Cycloaddition of Vinylphosphine Oxides to α-Oxy-o-xylylene as a route to Phosphorylated Naphthyl and Biaryl Scaffolds

Author:
Frynas, Sławomir; Łastawiecka, Elżbieta; Kozioł, Anna E.; Flis, Anna; Pietrusiewicz, K. Michał
Source:
Journal of organic chemistry 2019 v.84 no.4 pp. 1818-1832
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; aromatization; chemical bonding; cycloaddition reactions; moieties; optical isomerism; organic chemistry; organic compounds; oxides;     Show all 9 Subjects
Abstract:
... α-Oxy-o-xylylene, a highly reactive diene readily accessible from benzocyclobutenol, undergoes Diels–Alder reaction with vinylphosphine oxides, yielding the corresponding 2-phosphorylated 1-hydroxy-1,2,3,4-tetrahydronaphthalenes in excellent yields. Use of unsubstituted and trans-2-aryl-substituted vinylphosphine oxides leads to cycloadducts with complete regioselectivity and with cis/trans select ...
DOI:
10.1021/acs.joc.8b02659

19. Design and Synthesis of Cross-Link-Dense Peptides by Manipulating Regioselective Bisthioether Cross-Linking and Orthogonal Disulfide Pairing

Author:
Dong, Huilei; Meng, Xiaoting; Zheng, Xiaoli; Cheng, Xueting; Zheng, Yiwu; Zhao, Yibing; Wu, Chuanliu
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5187-5194
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; crosslinking; cysteine; disulfide bonds; disulfides; epitopes; isomers; organic chemistry; penicillamine; peptides; proteolysis;     Show all 11 Subjects
Abstract:
... Existing disulfide-rich peptides, both naturally occurring and de novo designed, only represent a tiny amount of the possible sequence space because natural evolution and de novo design only keep sequences that are structurally approachable by correct disulfide pairings. To bypass this limitation for designing new peptide scaffolds beyond the natural sequence space, we dedicate to developing novel ...
DOI:
10.1021/acs.joc.9b00164

20. Electrochemical Synthesis Strategy for Cᵥᵢₙyₗ-CF₃ Compounds through Decarboxylative Trifluoromethylation

Author:
Hong, Huanliang; Li, Yibiao; Chen, Lu; Li, Bin; Zhu, Zhongzhi; Chen, Xiuwen; Chen, Ling; Huang, Yubing
Source:
Journal of organic chemistry 2019 v.84 no.9 pp. 5980-5986
ISSN:
1520-6904
Subject:
regioselectivity,   etc   ; carboxylic acids; chemical reactions; chemical structure; electrolysis; electrosynthesis; organic chemistry; trapping;     Show all 8 Subjects
Abstract:
... An efficient decarboxylative trifluoromethylation of α,β-unsaturated carboxylic acids using the Langlois reagent as a trifluoromethyl precursor has been achieved by an electro-oxidative strategy. Under catalyst-free and external oxidant-free electrolysis conditions, a series of Cᵥᵢₙyₗ-CF₃ compounds are obtained with a high regioselectivity in good yields. The successful trapping of the CF₃ radical ...
DOI:
10.1021/acs.joc.9b00766