Indium-Mediated Asymmetric Barbier-Type Allylations: Additions to Aldehydes and Ketones and Mechanistic Investigation of the Organoindium Reagents
作者:Terra D. Haddad、Lacie C. Hirayama、Bakthan Singaram
DOI:10.1021/jo902173j
日期:2010.2.5
indium-mediated additions, solvent plays a major role in determining the nature of the organoindium intermediate and we observed the susceptibility of some allylindium intermediates to hydrolysis in protic solvents. Under our reaction conditions using a polar aprotic solvent, we suggest that an allylindium(III) species is the active allylating intermediate. In addition, we have observed the presence of
我们报告了一种简单,有效且通用的方法,用于在一锅合成中在Barbier型条件下进行芳香族和脂肪族醛和酮的铟介导的对映选择性烯丙基化,可提供非常好的收率的手性醇产品(高达99% )和对映体过量(最高93%)。我们的方法能够耐受各种官能团,例如酯,腈和酚。此外,当使用肉桂基溴化物(> 95/5 anti / syn)时,可以使用更多取代的烯丙基溴,例如巴豆基和肉桂基溴化物,提供中等的对映选择性(分别为72%和56%)和出色的非对映选择性。)。然而,使用巴豆基溴化物时的立体选择性差,并且在我们的方法下,其他官能化的烯丙基溴化物对醇产物的对映选择性低。在这些类型的铟介导的添加物中,溶剂在确定有机铟中间体的性质中起主要作用,我们观察到某些烯丙基铟中间体对质子溶剂水解的敏感性。在使用极性非质子传递溶剂的反应条件下,我们认为烯丙基(III)物种是活性烯丙基化中间体。此外,我们已经观察到整个反应过程中存在
Direct Synthesis of <i>B</i>-Allyl and <i>B</i>-Allenyldiisopinocampheylborane Reagents Using Allyl or Propargyl Halides and Indium Metal Under Barbier-Type Conditions
作者:Lacie C. Hirayama、Terra D. Haddad、Allen G. Oliver、Bakthan Singaram
DOI:10.1021/jo300260a
日期:2012.5.4
groups to aldehydes and ketonesusing B-chlorodiisopinocampheylborane (dDIP-Cl) and indium metal. Under Barbier-type conditions, indium metal was used to generate allyl- and allenylindium intermediates, and subsequent reaction with dDIP-Cl successfully promoted the transfer of these groups to boron forming the corresponding chiralboranereagents. The newly formed boranereagents were reacted with aldehydes
Catalytic Allylation of Aldehydes Using Unactivated Alkenes
作者:Shun Tanabe、Harunobu Mitsunuma、Motomu Kanai
DOI:10.1021/jacs.0c04735
日期:2020.7.15
and a chromium complex catalyst, enabling catalytic allylation of aldehydes with simplealkenes, including feedstock lower alkenes. The reaction proceeded under visible-light irradiation at room temperature and with high functional group tolerance. The reaction was extended to an asymmetric variant by employing a chiral chromium complex catalyst.
Chiral sulfoxides as activators of allyl trichlorosilanes in the stereoselective allylation of aldehydes
作者:Vincenzo De Sio、Antonio Massa、Arrigo Scettri
DOI:10.1039/c002988b
日期:——
Chiral aryl methyl sulfoxides proved to be efficient activators in the asymmetric allylation of aldehydes with allyl trichlorosilanes. High enantioselectivity was found in the case of electron-poor aldehydes. The high levels of diastereoselectivity and the detection of nonlinear effects have allowed the elucidation of some mechanistic aspects of the reaction.
monodentate spiro phenylphospholane ligand 4 was prepared from a readily accessible, enantiomerically pure 1,1'-spirobiindane-7,7'-diol in high yield. This ligand has proven to be efficient for Pd-catalyzed enantioselective allylation of aldehydes with allylicalcohols. Aromatic, heteroaromatic, and aliphatic aldehydes gave homoallylic alcohols in good enantioselectivities (up to 83% ee) and excellent