- Enantioselective α-Benzylation of Acyclic Esters Using π-Extended Electrophiles
-
The first asymmetric cooperative Lewis base/palladium catalyzed benzylic alkylation of acyclic esters is reported. This reaction proceeds via stereodefined C1-ammonium enolate nucleophiles. Critical to its success was the identification of benzylic phosphate electrophiles, which were uniquely reactive. Alkylated products were obtained with very high levels of enantioselectivity, and this method has been applied toward the synthesis of the thrombin inhibitor DX-9065a.
- Schwarz, Kevin J.,Yang, Chao,Fyfe, James W. B.,Snaddon, Thomas N.
-
supporting information
p. 12102 - 12105
(2018/09/11)
-
- Expeditious synthesis of helicenes using an improved protocol of photocyclodehydrogenation of stilbenes
-
An improved procedure has been developed for photodehydrocyclization of stilbenes for the synthesis of phenanthrenes and helicenes. This procedure involves the use of THF as a scavenger of hydriodic acid produced during iodine mediated photodehydrocyclization. The use of THF is advantageous due to its higher boiling point, lower cost and easy availability as compared to propylene oxide. The method is applied to synthesize a number of phenanthrenes and helicenes. ARKAT-USA, Inc.
- Talele, Harish R.,Chaudhary, Anju R.,Patel, Parthiv R.,Bedekar, Ashutosh V.
-
experimental part
p. 15 - 37
(2011/06/19)
-
- The effect of substituents on the syn-anti conformer ratio in naphthyl-based imidazolinium salts and their corresponding N-heterocyclic carbenes
-
Eight new N-heterocyclic carbenes (NHCs) featuring substituted naphthyl side chains were synthesized. These molecules are present in solution as a stable mixture of anti and syn conformers. Through careful tuning of the substituents on position 2 and 2,7
- Gatti, Michele,Wu, Linglin,Drinkel, Emma,Gaggia, Fiona,Blumentritt, Sascha,Linden, Anthony,Dorta, Reto
-
experimental part
p. 176 - 198
(2011/06/18)
-
- Synthesis of High Carbon Materials from Acetylenic Precursors. Preparation of Aromatic Monomers Bearing Multiple Ethynyl Groups
-
The synthesis of polyethynyl aromatics as starting materials for the preparation of highly cross-linked organic solids containing high atom fractions of carbon is described.Treatment of bromo- and iodoaromatic compounds with (trimethylsilyl)acetylene (TMSA) in the presence of palladium(O) and copper(I) in amine solvents yields (trimethylsilyl)ethynyl-substituted aromatics.The TMS protecting groups can be removed by hydrolysis with mild base.Compounds prepared by using this technique include 1,3-diethynylbenzene, 2,5-diethynylthiophene, 1,3-diethynyltetrafluorobenzene, 1,4-diethynyltetrafluorobenzene, 2-ethynylthiazole, 2,4-diethynylthiazole, 2,7-diethynylnaphthalene, hexakis((trimethylsilyl)ethynyl)benzene, tetraethynylthiophene, 2,5-bis((trimethylsilyl)ethynyl)-3,4-bis(3-hydroxy-3-methyl-1-butynyl)thiophene, 2,5-diethynyl-3,4-bis(3-hydroxy-3-methyl-1-butynyl)thiophene, 2,5-bis(4-(2-thienyl)butadiynyl)-3,4-bis(3-hydroxy-3-methyl-1-butynyl)thiophene, and 2,5-bis-(4-(2-thienyl)butadiynyl)-3,4-diethynylthiophene.
- Neenan, Thomas X.,Whitesides, George M.
-
p. 2489 - 2496
(2007/10/02)
-