Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
作者:Xiaolin Jiang、Zijun Huang、Mohamed Makha、Chen-Xia Du、Dongmei Zhao、Fang Wang、Yuehui Li
DOI:10.1039/d0gc01741h
日期:——
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element–hydrogen (E–H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium
Convenient One-Pot Method for Formylation of Amines and Alcohols Using Formic Acid and 1,1'-Oxalyldiimidazole.
作者:Tokujiro KITAGAWA、Junko ARITA、Atsuko NAGAHATA
DOI:10.1248/cpb.42.1655
日期:——
1, 1'-Oxalydiimidazole (7) reacts with formic acid (8) in acetonitrile at room temperature to give N-formyl-imidazole (5), which promptly undergoes aminolysis and alcoholysis to yield formamides (2) or formates (4).
Catalytic Enantioselective Michael Addition of α-Aryl-α-Isocyanoacetates to Vinyl Selenone: Synthesis of α,α-Disubstituted α-Amino Acids and (+)- and (−)-Trigonoliimine A
作者:Thomas Buyck、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201306663
日期:2013.11.25
title reaction in the presence of the catalyst 1 afforded Michael adducts in excellent yields and enantioselectivities. The adducts were readily converted into α,α′‐disubstituted α‐aminoacids. The enantioselective total synthesis of both (+)‐ and (−)‐trigonoliimine A was accomplished using one of the Michael adducts derived from this methodology. M.S.=molecular sieves.
Improved Procedure for N-Formylation of Amines to Formamides Using Formic Acid, Oxalyl Chloride and Imidazole.
作者:Tokujiro KITAGAWA、Junko ITO、Chinatsu TSUTSUI
DOI:10.1248/cpb.42.1931
日期:——
The reaction of imidazole (15) with formyl chloride (14), generated in situ by the action of oxalyl chloride (10) on formic acid (3), afforded N-formylimidazole (7), which is a convenient formylating reagent. This procedure was used to prepare N-formyl derivatives (2) of aliphatic, aromatic and heteroaromatic amines (1) under mild conditions.
Facile access to <i>N</i>-formyl imide as an <i>N</i>-formylating agent for the direct synthesis of <i>N</i>-formamides, benzimidazoles and quinazolinones
N-Formamide synthesis using N-formyl imide with primary and secondary amines with catalytic amounts of p-toluenesulfonic acid monohydrate (TsOH·H2O) is described. This reaction is performed in water without the use of surfactants. Moreover, N-formyl imide is efficiently synthesized using acylamidines with TsOH·H2O in water. In addition, N-formyl imide was successfully used as a carbonyl source in the