Catalytic Asymmetric Cyano-Ethoxycarbonylation Reaction of Aldehydes using a YLi<sub>3</sub>Tris(binaphthoxide) (YLB) Complex: Mechanism and Roles of Achiral Additives
Full details of a catalytic asymmetric cyano-ethoxycarbonylation reactionpromoted by a heterobimetallicYLi3tris(binaphthoxide) complex (YLB 1), especially mechanisticstudies, are described. In the cyanation reaction of aldehydes with ethyl cyanoformate, three achiral additives, H2O, tris(2,6-dimethoxyphenyl)phosphine oxide (3a), and BuLi, were required to achieve high reactivity and enantioselectivity
(2,6)3P=S] reacted with acids to form a novel mercaptophosphonium salt [(2,6)3P–SH]X, solution thermolysis of which in the absence or presence of triphenylphosphine resulted in the unusual desulfurization to give the tertiary phosphonium salts [(2,6)3P–OH]X. (2,6)3P=S also reacted with alkyl iodides or bromides under mild conditions to give stable (alkylthio)phosphonium salts [(2,6)3P–SR]X (R=Me, Et
METHOD FOR PRODUCING CATALYST FOR CYCLIC CARBONATE SYNTHESIS
申请人:MARUZEN PETROCHEMICAL CO., LTD.
公开号:US20160108071A1
公开(公告)日:2016-04-21
The present invention provides a method for easily and inexpensively producing a heterogeneous catalyst used to synthesize a cyclic carbonate by reacting an epoxide with carbon dioxide and having excellent catalyst activity; a catalyst obtained using said manufacturing method; and a method for synthesizing a cyclic carbonate using said catalyst.
A method for producing a catalyst that is used for the purpose of synthesizing a cyclic carbonate by subjecting to a reaction an epoxide with carbon dioxide, said method comprising the following steps (a) and (b):
(a) a step of obtaining a catalyst precursor having a haloalkyl group or a haloaryl group by reacting a silane compound with a silica gel in the presence of xylene, the silane compound having a haloalkyl group or a haloaryl group and
(b) a step of obtaining a catalyst for synthesizing a cyclic carbonate by reacting the catalyst precursor obtained in step (a) with a tertiary phosphine.
compound, Φ3PSe [Φ = 2,6-(MeO)2C6H3], showed that the P=Se bond distance [2.136(2) A] was the longest among those of the reported triarylphosphine selenides, that the P–C bond distances [av. 1.839 A] were longer than those of triphenylphosphineselenide, and that all the P···O interatomic distances [2.794—3.189 A] were shorter than the sum of the van der Waals radii, implying a direct electron-donative
(η5-Pentamethylcyclopentadienyl)rhodium(III) complexes bearing η1-P and η2-phosphino-phenoxide coordinations derived from (2,6-dimethoxyphenyl)diphenylphosphine: their preparation and reactions with Lewis bases
作者:Xiao-Hong Han、Yasuhiro Yamamoto
DOI:10.1016/s0022-328x(98)00523-3
日期:1998.6
p-TosCH2NC (c), and P(OCH2)3CMe) (d). Complex 5 reacted with Lewisbases (L) in the presence of NaPF6 to produce [Cp*Rh(MDMPP-P,O)(L)](PF6) 6 and could be also obtained from 3 and MDMPP. The CO ligand of 4a or 6a was labile and was replaced with isocyanide or phosphine to produce the corresponding complexes, whereas its reverse reaction did not occur. Conversion of 4d to 6d was also observed, but conversion