Table 1 Alkylation of N, N-diisopropylbenzamide with Thioanisolea.

From: Direct alkylation of N,N-dialkyl benzamides with methyl sulfides under transition metal-free conditions

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entry

base

x

1a Conv. (%)b

3aa yield (%)b

1

LiHMDS

1.2

8

<5

2

KHMDS

1.2

6

<5

3

LiTMP

1.2

>95

76

4

LDA

1.2

>95

94

5

n-BuLic

1.2

>95

21d

6

LiCH2TMS

1.2

>95

58

7e

LDA

1.1

>95

98 (93)

  1. aReaction Conditions: benzamide 1a (0.5 mmol), thioanisole 2a (1.0 mmol), base, THF (1.0 mL), 60 °C, 24 h. HMDS: bis(trimethylsilyl)amide; LDA: lithium diisopropylamide; LiTMP: lithium 2,2,6,6-tetramethylpiperidide.
  2. bNMR yields and conversions with 2-methyloxynaphthalene as an internal standard, isolated yield in parenthesis.
  3. c1.6 M in hexane.
  4. dButyl phenyl ketone (30% yield) and 5-phenylnonan-5-ol (14% yield) were obtained as by-products.
  5. eLDA (0.55 mmol), 2a (0.7 mmol), 40 °C.
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