Asymmetric lithiation trapping of N -boc heterocycles at temperatures above -78°C

Giacomo Gelardi; Graeme Barker; Peter O'Brien; David C. Blakemore

doi:10.1021/ol402395j

Asymmetric lithiation trapping of N -boc heterocycles at temperatures above -78°C

Giacomo Gelardi, Graeme Barker, Peter O'Brien^*, David C. Blakemore

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to -20°C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (-)-sparteine or the (+)-sparteine surrogate in the temperature range -50 to -20°C for short reaction times (2-20 min). Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered functionalized N-Boc heterocycles in 47-95% yield and 77:23-93:7 er. With N-Boc pyrrolidine, trapped products can be generated in ∼90:10 er even at -20°C.

Original language	English
Pages (from-to)	5424-5427
Number of pages	4
Journal	Organic Letters
Volume	15
Issue number	21
Early online date	15 Oct 2013
DOIs	https://doi.org/10.1021/ol402395j
Publication status	Published - 1 Nov 2013

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10.1021/ol402395j

Cite this

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title = "Asymmetric lithiation trapping of N -boc heterocycles at temperatures above -78°C",

abstract = "The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to -20°C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (-)-sparteine or the (+)-sparteine surrogate in the temperature range -50 to -20°C for short reaction times (2-20 min). Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered functionalized N-Boc heterocycles in 47-95% yield and 77:23-93:7 er. With N-Boc pyrrolidine, trapped products can be generated in ∼90:10 er even at -20°C.",

author = "Giacomo Gelardi and Graeme Barker and Peter O'Brien and Blakemore, {David C.}",

year = "2013",

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TY - JOUR

T1 - Asymmetric lithiation trapping of N -boc heterocycles at temperatures above -78°C

AU - Gelardi, Giacomo

AU - Barker, Graeme

AU - O'Brien, Peter

AU - Blakemore, David C.

PY - 2013/11/1

Y1 - 2013/11/1

N2 - The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to -20°C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (-)-sparteine or the (+)-sparteine surrogate in the temperature range -50 to -20°C for short reaction times (2-20 min). Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered functionalized N-Boc heterocycles in 47-95% yield and 77:23-93:7 er. With N-Boc pyrrolidine, trapped products can be generated in ∼90:10 er even at -20°C.

AB - The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to -20°C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (-)-sparteine or the (+)-sparteine surrogate in the temperature range -50 to -20°C for short reaction times (2-20 min). Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered functionalized N-Boc heterocycles in 47-95% yield and 77:23-93:7 er. With N-Boc pyrrolidine, trapped products can be generated in ∼90:10 er even at -20°C.

U2 - 10.1021/ol402395j

DO - 10.1021/ol402395j

M3 - Article

C2 - 24180685

AN - SCOPUS:84887069448

SN - 1523-7060

VL - 15

SP - 5424

EP - 5427

JO - Organic Letters

JF - Organic Letters

IS - 21

ER -