Olefin cross-metathesis (CM) provides a short and convenient entry to diverse trans-gamma-aminoenones. When exposed to either acid or Heck arylation conditions, these intermediates are converted to mono-, di-, or trisubstituted pyrroles. The value of this chemistry is demonstrated by its application to the tetrasubstituted pyrrole subunit of Atorvastatin.
Various allyl ethers were converted into the corresponding N-allylcarbamates usingchlorosulfonylisocyanate (CSI) via the stable allylic carbocation rather than β-lactam through [2+2] cycloaddition. The reaction of cinnamyl methyl ether with CSI afforded only methyl N-cinnamylcarbamate at 0°C, but at 20°C, it produced a mixture of methyl N-cinnamylcarbamate and methyl N-(1-phenylprop-2-enyl)carbamate
A synthetic method for N-protected allylic amines from allyl ethers using chlorosulfonyl isocyanate (CSI) is presented. The reaction of 4-phenylbut-2-enyl methyl ether (1i) with CSI afforded methyl N-(1-benzylallyl)carbamate (2i) and methyl N-(4-phenylbut-2-enyl)carbamate (3i) in a 1:1.1 ratio. On the other hand, 1-benzylallyl methyl ether (1k) afforded the same products in a 4.6:1 ratio. The reactions
benzyl carbocations was investigated using the novel technique for comparing the stability of carbocations in solution developed by using a simple CSI reaction with various ethers. The p-methoxycinnamyl carbocation was the most stable in our reactionsystem and the next stable carbocation was the p-methoxybenzyl carbocation. The stability of the other carbocations decreased with methacryl, t-butyl, cinnamyl
Aldehyde Selective Wacker Oxidations of Phthalimide Protected Allylic Amines: A New Catalytic Route to β<sup>3</sup>-Amino Acids
作者:Barbara Weiner、Alejandro Baeza、Thomas Jerphagnon、Ben L. Feringa
DOI:10.1021/ja902591g
日期:2009.7.15
A newmethod for the synthesis of beta(3)-amino acids is presented. Phthalimide protected allylic amines are oxidized under Wacker conditions selectively to aldehydes using PdCl(2) and CuCl or Pd(MeCN)(2)Cl(NO(2)) and CuCl(2) as complementary catalyst systems. The aldehydes are produced in excellent yields and exhibit a large substrate scope. Beta-amino acids and alcohols are synthesized by oxidation
Regioselective Cp*Ir(III)-Catalyzed Allylic C–H Sulfamidation of Allylbenzene Derivatives
作者:Amaan M. Kazerouni、Taylor A. F. Nelson、Steven W. Chen、Kimberly R. Sharp、Simon B. Blakey
DOI:10.1021/acs.joc.9b01816
日期:2019.10.18
In this study we report the development of the regioselective Cp*Ir(III)-catalyzed allylic C-H sulfamidation of allylbenzene derivatives, using azides as the nitrogen source. The reaction putatively proceeds through a Cp*Ir(III)-π-allyl intermediate and demonstrates exclusive regioselectivity for the branched position of the π-allyl. The reaction performs well on electron-rich and electron-deficient