31468-33-4Relevant academic research and scientific papers
Unified Synthesis of Polycyclic Alkaloids by Complementary Carbonyl Activation**
Christmann, Mathias,He, Guoli,List, Benjamin
supporting information, p. 13591 - 13596 (2021/05/07)
A complementary dual carbonyl activation strategy for the synthesis of polycyclic alkaloids has been developed. Successful applications include the synthesis of tetracyclic alkaloids harmalanine and harmalacinine, pentacyclic indoloquinolizidine alkaloid nortetoyobyrine, and octacyclic β-carboline alkaloid peganumine A. The latter synthesis features a protecting-group-free assembly and an asymmetric disulfonimide-catalyzed cyclization. Furthermore, formal syntheses of hirsutine, deplancheine, 10-desbromoarborescidine A, and oxindole alkaloids rhynchophylline and isorhynchophylline have been achieved. Finally, a concise synthesis of berberine alkaloid ilicifoline B was completed.
ESTERAMIDE SOLVENTS/COALESCING AGENTS IN PHYTOSANITARY, CLEANING, DEGREASING, STRIPPING, LUBRICATING, COATING, AND PIGMENT/INK COMPOSITIONS
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Page/Page column 17, (2011/07/29)
Esteramide compounds are useful solvents/coalescing agents for a variety of phytosanitary, cleaning, degreasing, stripping, lubricating, coating and pigment/ink compositions.
Stereoselectivity in reactions of atropisomeric lactams and imides
Bennett, D. Jonathan,Blake, Alexander J.,Cooke, Paul A.,Godfrey, Christopher R.A.,Pickering, Paula L.,Simpkins, Nigel S.,Walker, Matthew D.,Wilson, Claire
, p. 4491 - 4511 (2007/10/03)
A range of reactions of cyclic lactam systems is described in which an atropisomeric C-N axis controls the stereochemical outcome of ring substitution or addition. In the case of enantiopure menthol adducts, substitution via N-acyliminium intermediates occurred with essentially complete control. However, the range of nucleophiles that participate in the reaction is very limited and at present the removal of the N-aryl substituent is problematic. A six-membered enamide is of moderate configurational stability and the axis exerts synthetically useful levels of control over enolate alkylations of the system. A novel Lewis acid mediated enamide arylation process was identified.
Angiotensin Converting Enzyme Inhibitors: 1-Glutarylindoline-2-carboxylic Acid Derivatives
Gruenfeld, Norbert,Stanton, James L.,Yuan, Andrew M.,Ebetino, Frank H.,Browne, Leslie J.,et al.
, p. 1277 - 1282 (2007/10/02)
The preparation of a series of 1-glutarylindoline-2(S)-carboxylic acid derivatives, 6a-v and 21a-c, is described.The above compounds were tested for inhibition of angiotensin converting enzyme.The structure-activity relationship of the series is also discussed.Compound 6u, the most potent member of the series, had an in vitro IC50 of 4.8*10-9 M.Compound 6v, an ethyl ester of 6u, lowered blood pressure 70 mm in spontaneous hypertensive rats at an oral dose of 30 mg/kg.
Excited-State ? Succimidyl and Glutarimidyl Radicals: Reversible Ring Opening
Tlumak, Robert L.,Day, James C.,Slanga, Joseph P.,Skell, Philip S.
, p. 7257 - 7267 (2007/10/02)
The free-radical isomerization of N-bromosuccinimide to β-bromopropionyl isocyanate has been examined.Of the two varieties of succinimidyl radical (S? or S?), only the ? excited state undergoes the ring opening to the β propionyl isocyanatyl radical.The conversion optimally takes place in >95percent yield.The dependence of NBS concentration along with results obtained from deuterium labeling studies indicate that the ring opening of S? is a reversible process.This explains the failure of N-chlorosuccinimide to produce β-chloropropionyl isocyanate, as well as the increase in ring-opened product for N-bromosuccinimides upon methyl substitution at the 2- and/or 3-position of the succinimidyl ring, since the open-chain radical intermediates are more stable.In the N-bromoglutarimide system, methyl groups on the 2-position are required for the glutarimidyl radicals to undergo the isomerization, ultimately producing isocyanates.The radical-chain nature of these systems is confirmed.
