Enantio- and diastereoselective titanium-TADDOLate catalyzed addition of diethyl and bis(3-buten-1-yl) zinc to aldehydes a full account with preparative details
作者:Dieter Seebach、Albert K. Beck、Beat Schmidt、Yan Ming Wang
DOI:10.1016/s0040-4020(01)89373-x
日期:1994.4
enantioselective addition of alkyl groups from organozinc reagents to aldehydes (19 examples). With 0.05 – 0.20 equiv. of the diisopropoxy-Ti-TADDOLate bearing four 2-naphthyl groups and 1.2 equiv. of Ti(OCHMe2)4 in toluene or ether solution the best results are obtained: ≥ 98 : 2 enantiomer ratios with all types of aldehydes tested (saturated, olefinic, and acetylenic aliphatic, aromatic, and heteroaromatic)
Organolanthanide-Catalyzed Hydroamination/Cyclization. Efficient Allene-Based Transformations for the Syntheses of Naturally Occurring Alkaloids
作者:Victor M. Arredondo、Shun Tian、Frank E. McDonald、Tobin J. Marks
DOI:10.1021/ja984305d
日期:1999.4.1
organolanthanide complexes efficiently mediate highly diastereoselective intramolecular hydroamination/cyclization (IHC) reactions under mild conditions. The turnover-limiting step in these catalytic cycles is proposed to be intramolecular insertion into the Ln−N bond of the proximal allenic CC linkage, followed by rapid protonolytic cleavage of the resulting Ln−C bond. The rate and selectivity of the insertion
CITU: A Peptide and Decarboxylative Coupling Reagent
作者:Justine N. deGruyter、Lara R. Malins、Laurin Wimmer、Khalyd J. Clay、Javier Lopez-Ogalla、Tian Qin、Josep Cornella、Zhiqing Liu、Guanda Che、Denghui Bao、Jason M. Stevens、Jennifer X. Qiao、Martin P. Allen、Michael A. Poss、Phil S. Baran
DOI:10.1021/acs.orglett.7b03121
日期:2017.11.17
Tetrachloro-N-hydroxyphthalimide tetramethyluronium hexafluorophosphate (CITU) is disclosed as a convenient and economical reagent for both acylation and decarboxylative cross-coupling chemistries. Within the former set of reactions, CITU displays reactivity similar to that of common couplingreagents, but with increased safety and reduced cost. Within the latter, increased yields, more rapid conversion, and a
Nickel-Catalyzed Difluoroalkylation–Alkylation of Enamides
作者:Chang Xu、Zhi-Fang Yang、Lun An、Xingang Zhang
DOI:10.1021/acscatal.9b02488
日期:2019.9.6
Nickel-catalyzed carbodifunctionalization of alkenes is an efficient strategy for the construction of C–C bonds. However, applications of the strategy in dialkylation of alkenes remain underdeveloped due to the difficulties in suppressing competitive side reactions. We now describe a nickel-catalyzed tandem reaction by difluoroalkylation–alkylation of N-vinyl 2-pyrrolidinone with difluoroalkyl bromides
Congested C(sp3)-rich architectures enabled by iron-catalysed conjunctive alkylation
作者:Tong-De Tan、Juan M. I. Serviano、Xiaohua Luo、Peng-Cheng Qian、Patrick L. Holland、Xinglong Zhang、Ming Joo Koh
DOI:10.1038/s41929-024-01113-8
日期:——
metals has revolutionized the formation of carbon–carbon bonds in organic synthesis. However, the challenge of forming multiple alkyl–alkyl bonds in crowded environments remains largely unresolved. Here we report the regioselective functionalization of olefins with sp3-hybridized organohalides and organozincreagents using a simple (terpyridine)iron catalyst. Aliphatic groups of various sizes are successfully