Mechanistic Studies of an Antibody-Catalyzed Elimination Reaction
摘要:
Catalytic antibody 43D4-3D12, which was generated against the substituted tertiary amine 1, catalyzes the elimination of HF from beta-fluoroketone 2. We have cloned and produced the antibody as a chimeric Fab and constructed a model of the active site-substrate complex. Mutagenesis studies of the active site indicate that Glu(H)50 acts as the general base and suggest that Tyr96(L) may also play a role in the elimination reaction. Antibody 43D4-3D12 also efficiently catalyzes the elimination of HBr from substrate 4 by an E2 mechanism, again involving selective abstraction of the proton beta-to the nitrophenyl ring by Glu(H)50. The antibody-catalyzed reaction affords predominantly the internal olefins, whereas the major product resulting from the uncatalyzed reaction is the alcohol, which arises from the competing substitution reaction. In addition, antibody 43D4-3D12 catalyzes an acetal hydrolysis reaction in which Glu(H)50 likely acts as a general acid. These studies point to the success of this particular hapten design strategy in generating an active site with a desired catalytic functional group. They also illustrate the utility of using related reactions as mechanistic probes of biological catalysis.
Redox Chain Reaction-Indole and Pyrrole Alkylation with Unactivated Secondary Alcohols
作者:Xinping Han、Jimmy Wu
DOI:10.1002/anie.201209810
日期:2013.4.22
Secondary role: Indole and pyrrole derivatives are alkylated with unactivated secondary aliphatic alcohols by a Brønsted acid‐catalyzed redox chain reaction mechanism. Broad functional‐group tolerance has been demonstrated and preliminary studies suggest that 1,4‐reduction of a putative indolyl carbocation is the dominant mechanistic pathway.
Octahydro-10-oxo-6H-pyridazo [1,2-a] [1,2] diazepin-Derivate, Zwischenprodukte und Verfahren zu deren Herstellung sowie diese enthaltende Arzneimittel
申请人:F. HOFFMANN-LA ROCHE AG
公开号:EP0271795A2
公开(公告)日:1988-06-22
Verbindungen der Formel
worin R¹ und R² je Wasserstoff, C₁-C₁₀-Alkyl, Adamantyl-(C₁-C₄-alkyl) oder (C₂-C₆-Alkanoyloxy)-(C₁-C₄-alkyl) bedeuten,
und pharmazeutisch verwendbare Säureadditionssalze davon besitzen antihypertensive Eigenschaften und können demnach in Form pharmazeutischer Präparate als Arzneimittel verwendet werden. Sie können nach bekannten Methoden hergestellt werden.
Metal–Organic Capsules with NADH Mimics as Switchable Selectivity Regulators for Photocatalytic Transfer Hydrogenation
作者:Jianwei Wei、Liang Zhao、Cheng He、Sijia Zheng、Joost N. H. Reek、Chunying Duan
DOI:10.1021/jacs.9b05351
日期:2019.8.14
capsule, nitrogroups are highly selectively reduced through a typical 1e- hydrogenation. By combining photoinduced 1e- transfer regeneration outside the cage, both the 1e- and 2e- hydrogenation can be switched controllably by varying the concentrations of the substrates and the redox potential of electron donors. This promising alternative approach, which could proceed under mild reaction conditions
Mechanistic Studies of an Antibody-Catalyzed Elimination Reaction
作者:Floyd E. Romesberg、Mark E. Flanagan、Tetsuo Uno、Peter G. Schultz
DOI:10.1021/ja9738992
日期:1998.6.1
Catalytic antibody 43D4-3D12, which was generated against the substituted tertiary amine 1, catalyzes the elimination of HF from beta-fluoroketone 2. We have cloned and produced the antibody as a chimeric Fab and constructed a model of the active site-substrate complex. Mutagenesis studies of the active site indicate that Glu(H)50 acts as the general base and suggest that Tyr96(L) may also play a role in the elimination reaction. Antibody 43D4-3D12 also efficiently catalyzes the elimination of HBr from substrate 4 by an E2 mechanism, again involving selective abstraction of the proton beta-to the nitrophenyl ring by Glu(H)50. The antibody-catalyzed reaction affords predominantly the internal olefins, whereas the major product resulting from the uncatalyzed reaction is the alcohol, which arises from the competing substitution reaction. In addition, antibody 43D4-3D12 catalyzes an acetal hydrolysis reaction in which Glu(H)50 likely acts as a general acid. These studies point to the success of this particular hapten design strategy in generating an active site with a desired catalytic functional group. They also illustrate the utility of using related reactions as mechanistic probes of biological catalysis.