1
|
Guo R, Adak S, Bellotti P, Gao X, Smith WW, Le SN, Ma J, Houk KN, Glorius F, Chen S, Brown MK. Photochemical Dearomative Cycloadditions of Quinolines and Alkenes: Scope and Mechanism Studies. J Am Chem Soc 2022; 144:17680-17691. [PMID: 36106902 PMCID: PMC9840784 DOI: 10.1021/jacs.2c07726] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Photochemical dearomative cycloaddition has emerged as a useful strategy to rapidly generate molecular complexity. Within this context, stereo- and regiocontrolled intermolecular para-cycloadditions are rare. Herein, a method to achieve photochemical cycloaddition of quinolines and alkenes is shown. Emphasis is placed on generating sterically congested products and reaction of highly substituted alkenes and allenes. In addition, the mechanistic details of the process are studied, which revealed a reversible radical addition and a selectivity-determining radical recombination. The regio- and stereochemical outcome of the reaction is also rationalized.
Collapse
Affiliation(s)
- Renyu Guo
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana47405, United States
| | - Souvik Adak
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana47405, United States
| | - Peter Bellotti
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 36, 48149Münster, Germany
| | - Xinfeng Gao
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana47405, United States
| | - W Walker Smith
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana47405, United States
| | - Sam Ngan Le
- Department of Chemistry and Biochemistry, Oberlin College, 119 Woodland Street, Oberlin, Ohio44074, United States
| | - Jiajia Ma
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 36, 48149Münster, Germany
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California90095, United States
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 36, 48149Münster, Germany
| | - Shuming Chen
- Department of Chemistry and Biochemistry, Oberlin College, 119 Woodland Street, Oberlin, Ohio44074, United States
| | - M Kevin Brown
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana47405, United States
| |
Collapse
|
2
|
Nakahashi TK, Kambayashi J, Nakamura T, Le SN, Yoshitake M, Tandon NN, Sun B. Platelets in nonresponders to epinephrine stimulation showed reduced response to ADP. Thromb Res 2001; 104:127-35. [PMID: 11672756 DOI: 10.1016/s0049-3848(01)00354-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
It has been reported that platelets from some healthy donors did not respond to epinephrine (Epi). To identify the cause for the lack of response, we examined the alpha(2) adrenoceptor in the platelets and their signal transduction pathways. No differences in the genomic (-2076 to 1526 bp) and coding region of alpha(2A) adrenoceptor complementary DNA (cDNA) were found between the responders (R) and nonresponders (NR). No expression of alpha(2B) or alpha(2C) adrenoceptor was detected in platelets. When UK14,304 was used to induce platelet aggregation, similar effect to Epi was observed between R and NR, and any involvement of the alpha(1) and beta adrenoceptor was ruled out. Radioligand binding assay showed similar number of alpha(2) binding sites between the two groups (139+/-25/platelet vs. 145+/-37/platelets). However, platelets from NR showed a weaker response to adenosine diphosphate (ADP, 52.3+/-17.8% vs. 80.5+/-8.7% from R, P<.01). In the presence of P2Y(1) antagonist adenosine 3',5'-diphosphosulfate (A3P5PS), ADP failed to induce platelet aggregation in NR (7.8+/-4.7% vs. 64.7+/-11.2% in R, P<.01). Addition of SQ22,536 to inhibit adenylyl cyclase did not convert NR to R. These observations demonstrate that there is an impaired platelet responsiveness to ADP as well as to Epi in NR, due to a difference in downstream of the signal transduction pathway but independent of adenylyl cyclase inhibition.
Collapse
Affiliation(s)
- T K Nakahashi
- Vascular Biology and Thrombosis, Maryland Research Laboratories, Otsuka Maryland Research Institutes, LLC, Rockville, MD 20850, USA
| | | | | | | | | | | | | |
Collapse
|